flurescent multilayer disc seminar or presentation report
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29-12-2009, 03:49 PM



.doc   flurescent multilayer seminar report.doc (Size: 7.59 MB / Downloads: 984)
ABSTRACT


C3D or constellation 3Dâ„¢s innovative technology enables the recording,reading and storing of information on many layers within a storage media.Flourescent materials are embedded in the pits and grooves of each layer of the media and information is then stored and retrieved using the principles of fluorescence ,instead of optical reflection as currently used with CDs and DVDs .The media can be produced in card or disk format of any size. This technology holds the promise of exciting new applications and vast commercial potential. The ability to store data on multiple layers within the media allows the creation of compact removable storage devices with amazing capacity.

Constellation 3Dâ„¢s planned first generation disk, in standard (120mm diameter and 1.2mm thick)DVD format, will store up to 140 gigabytes in 10 layers .As production techniques using this technology evolve ,the number of layers and the distance between them will shrink ,eventually allowing terabytes of data to be stored on a single disk. Factors such as the ability to read simultaneously from multiple data layers allow exponential increase in data access and retrieval speeds, eventually resulting in retrieval speeds of 1 gigabyte per second.

Other new technologies, such as the simultaneous reading of multiple sectors within a single layer, can bring yet further increase in speed and provides true 3-dimensional data access/retrieval time. The implications of all of this for the data storage industry are enormous, as the technology offers quantum improvements in storage capacity, access/retrieval speeds and cost per gigabyte “in a compact, rugged and portable media format. A whole new range of applications and devices will be spawned, which take advantage of these superior capabilities.


INTRODUCTON

Requirements for removable media storage devices (RMSDs) used with personal computers have changed significantly since the introduction of the floppy disk in 1971. At one time, desktop computers depended on floppy disks for all of their storage requirements. Even with the advent of multigigabyte hard drives, floppy disks and other RMSDs are still an integral part of most computer systems, providing.

Transport between computers for data files and software
Backup to preserve data from the hard dive
A way to load the operating system software in the event of a hard failure.

Data storage devices currently come in a variety of different capacities, access time, data transfer rate and cost per Gigabyte. The best overall performance figures are currently achieved using hard disk drives (HDD), which can be integrated into RAID systems (reliable arrays of inexpensive drives) at costs of $10 per GByte (1999). Optical disc drives (ODD) and tapes can be configured in the form of jukeboxes and tape libraries, with cost of a few dollars per GByte for the removable media. However, the complex mechanical library mechanism serves to limit data access time to several seconds and affects the reliability adversely.

Most information is still stored in non-electronic form, with very slow access and excessive costs (e.g., text on paper, at a cost of $10 000 per GByte).

Some RMSD options available today are approaching the performance, capacity, and cost of hard-disk drives. Considerations for selecting an RMSD include capacity, speed, convenience, durability, data availability, and backward-compatibility. Technology options used to read and write data include.

Magnetic formats that use magnetic particles and magnetic fields.

Optical formats that use laser light and optical sensors.

Magneto-optical and magneto-optical hybrids that use a combination of magnetic and optical properties to increase storage capacity.

The introduction of the Fluorescent Multi-layer Disc (FMD) smashes the barriers of existing data storage formats. Depending on the application and the market requirements, the first generation of 120mm (CD Sized) FMD ROM discs will hold 20 - 100 GigaBytes of pre -recorded data on 12 ” 30 data layers with a total thickness of under 2mm.In comparison, a standard DVD disc holds just 4.7 gigabytes. With C3D™s (Constellation 3D) proprietary parallel reading and writing technology, data transfer speeds can exceed 1 gigabit per second, again depending on the application and market need.



WHY FMD?

Increased Disc Capacity
DVD data density (4.7 GB) on each layer of data carriers up to 100 layers. Initially, the FMD disc will hold anywhere from 25 ” 140 GB of data depending on market need. Eventually a terabyte of data on a single disc will be achievable.

Quick Parallel Access and Retrieval of Information
Reading from several layers at a ime and multiple tracks at a time nearly impossible using the reflective technology of a CD/DVD ” is easily achieved in FMD. This will allow for retrieval speeds of up to 1 gigabyte per second.

Media Tolerances
By using incoherent light to read data the FMD/FMC media will have far fewer restrictions in temperature range, vibration and air- cleanness during manufacturing. And will provide a considerably more robust data carrier than existing CD and DVDs.

Usage Flexibility
FMD/FMC presents a wide variety of potential media sizes and types (read only, write-able and re-writeable) for a broad range of applications.

Potential for Further Growth
The technology is young and will grow and evolve, providing a clear road map for the future of data storage.


FMD ROM Disc and Drive

The introduction of the Fluorescent Multi-layer Disc (FMD) smashes the barriers of existing data storage formats. Depending on the application and the market requirements, the first generation of 120mm (CD Sized) FMD ROM discs will hold 20 - 100 Gigabytes of pre recorded data on 12 - 30 data layers with a total thickness of under 2mm. In comparison, a standard DVD disc holds just 4.7 gigabytes. With C3Dâ„¢s proprietary parallel reading and writing technology, data transfer speeds could exceed 1 gigabyte per second, again depending on the application and market need. Constellation 3D has signed several key strategic partnerships to assist in the development of Fluorescent Multilayer technology.



FMD drives will be similar in size, design and price to CD and DVD drives and players currently on the market. Lasers and laser focusing technology will be the same and only minor modifications are required in the signal processing unit to allow for the reading of the incoherent light emitted by an FMD disc rather than the coherent light of a CD or DVD.

Early applications for this exciting new product include digital cinema and HDTV players, internet content streaming and data warehousing. As consumer storage needs grow, so too will the market for FMD discs and drives. The technologyâ„¢s robust nature and low manufacturing cost make it ideally suited for broad market acceptance.



FMD ROM Disk

FMD WORM Disc and Drive

Just as previous optical disc products have evolved from pre-recorded to recordable technologies, the next generation of fluorescent multi- layer technologies will give users the ability to write and record their own content for future playback. FMD WORM media will be based on the same simple technologies as ROM but will use fluorescent dyes capable of the phase change need for recording. One advantage of the media will be its ability to have both WORM and ROM on the same carrier.


Concept FMD Peripheral Drive

WORM drives will have the same cost structure as ROM drives but incorporate a slightly different laser configuration to allow for writing and reading.

ClearCard Disc and Drive

To meet the capacity needs of the growing mobile computing marketplace, including everything from E books to MP3 players to PDAâ„¢s and (IPS units, Constellation 3D has announced a miniaturized version of its Fluorescent Multi-layer technology.

ClearCard is a credit card sized media. As with the FMD disc technology, the first product release will be a ROM version with future releases to be WORM versions or combined WORM and ROM versions.

First generation WORM and ROM products will likely hold up to 10 gigabytes. This gives ClearCard hundreds of times the potential storage flash memory now used in many mobile applications, at a fraction of the manufacturing cost.
The ClearCard drive will be a miniaturized version of the FMD drive with the low power requirements and small size required by the mobile market.



Concept FMC Peripheral Drive

Future Disks & Cards

By adding layers and taking advantage of blue laser technology, second and third generation cards and discs will have capacities up to and exceeding 1 Terabyte (1,000 Gigabytes). In addition Read/Write versions of disc and card are planned.



DIGITAL DATA STORAGE

Mass Storage Products

Data storage devices currently come in a variety of difterent capacities, access time, data transfer rate and cost per Gigabyte. The best overall performance figures are currently achieved using hard disk drives (HDD), which can be integrated into RAID systems (reliable arrays of inexpensive drives) at costs of $10 per GByte. Optical disc drives (ODD) and tapes can be configured in the form of jukeboxes and tape libraries, with cost of a few dollars per GByte for the removable media. However, the complex mechanical library mechanism serves to limit data access time to several seconds and affects the reliability adversely. Most information is still stored in non-electronic form, with very slow access and excessive costs (e.g., text on paper, at a cost of $10 000 per GByte).

Technologies

Figure shows the basic components of different recording technologies. Magnetic disk heads fly on a slider at a distance of approximately 0.1 micrometer above the surface of the storage medium.



During the writing process small magnetic domains are written, the magnetic fields of these domains are detected during the read process. The information can be overwritten indefinitely. The areal density of magnetic recording has grown by approximately 60% per year during the last decade. Devices with 10 Gbit/sqi are currently in production, 3OGbit/sqi have been demonstrated. However, there appears to be a limit - the super paramagnetic limit where the magnetic domains become unstable, thus limiting further growth in the areal density achievable. In optical disc drives (ODD) such as CD, DVD and MO, light from a semiconductor laser is focused onto the storage layer to perform writing/reading. The storage layer is protected through the disc substrate or a thick overcoat, making this technology well suited for removable media. The achievable storage density is determined by the size of the recording spot, which in turn is determined by the wavelength of the laser light, resulting (with current 650 nm red lasers) in a maximum a real density of 5 bits/micrometer 2. Advances in laser technology leading to utilization of 480 nm blue lasers will increase this density four-fold. Advanced optical techniques using magneto-optic MSR,MAMMOS, HYBRID, near-field and super-RENS technologies are expected to achieve areal densities of approximately 50 bit/ sqi over the next ten years, making capacities of up to 100 GByte per disk possible on CD/DVD sized 120-mm diameter, 1.2-mm thick disks.These systems will need to use blue lasers, complex-structured media and extremely sophisticated optics and mechanics. Areal densities of various techniques are shown in Figure 2.

Volumetric Recording

As can be seen from the above, the storage density of media using current HDD and ODD technologies is limited due to the need to store data within a thin layer near the surface of the media.


Holographic Storage

With the advent of lasers in the 1960s, storage in 3D has been proposed by using holographic techniques. However, attempts at commercialisation have so far failed, primarily due to lack of suitable storage materials for media manufacturing.

Multi-layer Storage

In a multi-layer card or disc, several layers are integrated into the media, separated from each other by distances as small as 15 micrometers. A recording laser beam is focused onto one layer at a time writing and reading the layers separately.

Reflective Multi-layer

The concept of multilayer optical discs has been proposed by Philips and IBM, and has been demonstrated up to several layers. The DVD is an implementation of this concept with two layers. However, for many layers the coherent nature of the probing laser beam causes interference scatter and intra-layer cross talk”the combination of which results in a signal that is degraded to unacceptable levels. Following its research into the feasibility of producing a 6-layer optical disc, IBM announced that it would not proceed to production of such devices due to the many difficulties involved in its implementation and thus commercialisation.

Fluorescent multilayer

The concept of multi-layer, fluorescent cards/discs (FMD/C) is a unique breakthrough; solving the problems of signal degradation. Here the storage layer is coated with a fluorescent material. When the laser beam hits the layer, fluorescent light is emitted. This emitted light has a different wavelength from the incident laser light”slightly shifted towards the red end of the light spectrum”and is incoherent in nature, in contrast to the reflected light in current optical devices. The emitted light is not affected by data or other marks, and transverses adjacent layers undisturbed. In the read-out system of the drive the light is filtered, so that only the information-bearing fluorescent light is detected, thus reducing the effect of stray light and interference.

Theoretical studies, confirmed by experimental results, have shown that in conventional reflection systems the signal quality degrades rapidly with the number of layers .In fluorescent read out system, on the other hand the signal quality degrades much more slowly with each additional layer (see below). Research has shown that media containing up to a hundred layers are currently feasible, there by increasing the potential capacity of a single card or disk to hundreds of Gigabytes. Use of blue lasers would increase the capacities to over 1 Terabyte.

FMD/C Advantages

The main advantages of multilayer fluorescent read out are:
1. The multi-layer system is optically transparent and homogeneous.
2. Low absorption in each layer.
3. No absorption for the emitted signal fluorescent light.
4. Lower than CD/DVD sensitivity to imperfections in media and drives. The fluorescent technique does not depend on interference effects and requires less stringent manufacturing tolerances for media and drives.
5. The emitted fluorescent light from any given layer is non coherent, eliminating the problem of parasite inter-ference.
6. The limited lateral spatial resolution for this system is twice that for coherent-light-based systems (e.g. current CD/DVD reflective systems). In the case of FMD/C, this two-fold improvement over three (3) dimensions, results in an eight-fold improvement in achievable data density.
7. FMD technology is compatible with current CD and DVD formats having the capacity to handle the same data rates over each of its layers

The above qualities make FMC unique in its techno-logical capability to facilitate production of a multilayer optical card, ClearCard, in any form factor including postage-stamp-sized SmartMedia, credit card sized ClearCard, or otherwise. The capacity and speed of reading from these cards can be enormous. For instance, with the level of existing technology ClearCard of 16 cm 2 of area with 50 layers can furnish consumers with 1 terabyte capacity and, through parallel access to all its layers, allow over 1 gigabyte/s speed of reading. Another major advantage for both cards and discs using the technology is the ability to read data on every layer of the media in parallel, thereby allowing the potential of much greater data transfer rates compared with single layer media. This can be combined with parallel reading from multiple sectors of the same layer to increase data speeds still further, producing 3-dimensional data transfer.


STATUS OF DEVELOPMENT

A principal obstacle to the development of small portable appliances with large data storage capacity is the lack of inexpensive small size memory carriers that can store Gigabytes of information in a media allowing fast data transfer rates. Constellation 3Dâ„¢s fluorescent multi-layer technology enables the production, in a wide variety of form factors, of storage media satisfying these criteria.

Media

The FMD/C media consist of several plastic (polycar-bonate) substrates bonded together.The substrates contain surface structures (pits) that a re filled with a proprietary fluorescent storage material.



A major design goal in the development of CD/DVD replacements using this technology was to allow a simple and cost-effective upgrade for existing manufacturers of optical devices. FMD technology enables the use, with only relatively minor changes (such as impregnation with flourescent materials), of existing components and processes from high volume products such as CDs/DV D s, and avoids the need for new infrastructure for media and drive production. The number of process steps per layer is actually reduced, because a reflective metallic layer is not required. For the individual layer of a multilayer disc, metal stampers containing the digital content are produced in a mastering process that is similar to CD or DVD processes. For FMD/C, two replication processes have been developed:

1. Hot-embossing: In this process, thin sheets of polycarbonate are embossed on both sides with the metal stampers at elevated temperatures. The embossed pits are then filled with the fluorescent dye. After the dye is cured, the individual sheets are bonded together under pressure, resulting in a storage media having multiple layers. Figure 4 shows a 7-layer media.

2. Photo-polymerisation (2P) process: In this method, layers are replicated one after the other the formation of thin replicas. This technology has been demonstrated for up to ten layers.

Fluorescent Material

Perhaps the most critical component of the storage media is the fluorescent material that converts the incident (incoherent) laser light into incoherent fluorescent light. The materials and associated drives for read-only cards and discs (ROM) are currently the most mature FM technology. Recordable materials and associated drives have also been developed and demonstrated, and improvement of this FM technology continues. FMD/C write/read technology based on proprietary photochromic substances has been demonstrated in Constellation 3Dâ„¢s laboratories during write! read / erase / re-write experiments.



FMD/C ROM (read only) Devices

There are several requirements for the fluorescent materials:

1. The fluorescent ROM material has to be compatible with the substrate material
2. The absorption wavelength should be the same wavelength as commercially available, low-cost semiconductor lasers used in CD players
3. The emitted fluorescent light should be wavelength-shifted by at least 35 nm, to allow easy separation of the incident and signal light
4. The material should have a high conversion efficiency
5. The material should have a refractive index close to that of the polycarbonate
6. The material should remain stable over a reasonable time
7. Fast response ” 1 ns

Light-sensitive material: The photo-polymer composition (PPC) is a mixture of monomers and oligomers with photo-initiator, which initiates the polymerisation process under radiation in a certain spectral range. PPC serves as the substrate for the data carrier, oxazine- 1, methylene blue, methylene violet and other red dyes serve as the photo-initiator.

Pit-filling process: The working surface of a polycar-bonate disc is a plane with pits: cavities 0.5 micrometer in size, located in a certain order. Such micro relief can be filled with liquid monomeric or oligomeric substances that turn into hard polymer substances when subjected to UV light. The substances fill the pits and overflow to form a thicker layer on the media surface. The ratio of layer thickness in the pit to its thickness on the surface makes the contrast. One of the main tasks confronting the scientists in developing the process of filling the pits, creating the overflow and choosing the material, was to find the combination of these that provided the largest such contrast.

FMD/C Recordable (write once read many) Devices

In additiqn requirements for ROM media, RECORDABLE media require the following:

A writing proess where the writing light is able to turn on or off the fluorescence
A threshold level above which the fluorescent material is changed by the power level of the write, and below which the material is unchanged during any subsequent read-out

Currently 2 techniques have been developed:

Thermal bleaching: In this technique the material is initially fluorescent. The incident write light heats the material, destroying the fluorescence. The write parameters are similar to CD/R recording and the standard optical-writing 15-mW laser is well suited for providing CD-R equivalent data-writing rates. Materials suitable for applying this technique for use with red, green and blue laser wavelengths have been developed.

Photochemical reaction: Materials of this class are initially not fluorescent, and the write light initiates photo-chemical reactions, thereby creating fluorescence. The highly non-linear process associated with this reaction causes an effective threshold. Because no heating is involved, the required write power is low, allowing even light emitting diodes (LED arrays) to be used. With LED arrays, pages of information can be written simultaneously, thereby additionally enabling card applications. Current materials are sensitive to green and violet wavelengths. Constellation 3D is currently applying for further patents in respect of its FMD/C RECORD-ABLE devices, and further details on this technology will be published thereafter.

Results

10-layer discs with CD type density have been demon-strated (650 Mbyte per layer).

The above mentioned requirements have been fulfilled:

1. 650-nm laser, 680-nm peak of the fluorescent light
2. Stable media, no degradation during read-out
3. The conversion efficiency is more than 90%
4. The time response is approximately one nanosecond The saturation level is with 1 MW/cm2, above the read power intensity

Note: In a disc player device demonstrated in Israel , digital audio was played using different content from each of the layers. 10-layer and 20- layer ClearCard was demonstrated as well.

FMC Clearcard Reader

Figure shows the device for retrieving data from a fluorescent multilayer card (FMC)-ClearCard.

A semiconductor laser produces a beam, which is then focused on a selected layer of the card. A cylindrical lens forms a 500â„¢2 mm line, which by means of a scanning mirror, scans across a page area of the card The induced fluorescent light is imaged to a CCD array.



A frame grabber receives data from the CCD. In the subsequent image processing step the image is aligned, distortions are corrected, the image is thresholded and digital data is generated. Figure 6 shows a magnified fragment of a page during the decoding process.

FMD Disc Drive

A schematic diagram of a FMD drive is shown in Figure. The drives have most componens common with CD/DvD



Systems: Laser, beam-forming optics, spindle, tracking/ focusing actuators control electronics, data channel, data interface. The only additional components are filters to separate the fluorescent light from the laser light, and an optical element to correct for different optical path lengths in the storage medium, depending on the selected layer. Modifications in the electronics include detector circuit with higher sensitivity and the addition of servo electronics to address different layers within the multi-layer disc.



50-GB Disc Project

Principle Scheme of Disc and Reading System

The principle scheme of a 50-GB disc is shown in Figure.


Disc
¢ Disk diameter ” 130 ±0.3 mm
¢ Substrate width from objective side ” 0.6 m
¢ Number of layers ” 12
¢ Distance between layers ” 25 ±5 m
¢ Total width. of information area - 275 m
¢ Format - modified DVD
¢ Distance between tracks ” 0.8 m
¢ Channel bit length - 5/4 of that of DVD
¢ Pitwidth”0.5 Elm
¢ Pitdepth”O.5 m
¢ Information capacity - 50.8 GB




Reading system

¢ Laser ” single-mode diode pumped CW with stabilisation
¢ Laser power ” 10 mW
¢ Wavelength - 532 nm
¢ Aspheric objective with NA = 0.5
¢ Objective lens is designed for 8 10-m thickness of substrate
¢ Lens and compensator have wideband antireflection coatings for 500-700 nm

Principle diagram of reading head

The principle diagram of the head is shown in figure.



¢ Single lens objective with NA=0.5
¢ Parallel beam
¢ Spatial filtration by means of matching of pit image and photo detector size

Inter-track cross talk

The role of the information layer image on the detector surface is
¢ Spatial filtration is provided by matching of pits image and photo detector sizes
¢ Magnification of the system ” 20
¢ Detector surface area serves as aperture
¢ Photo detector size is 20 -20 mm
¢ Detector collection coefficient is 90% for useful fluorescent signal
¢ Signal-to-noise (from neighbor tracks) ratio is 190

Interlayer cross-talks

The HF component of interlayer cross-talk is negligibly small Even integral photo-detector illumination by all neighbour layers is small Spatial filtration system described above with distance between layers equal to 25 [ leads to integral background illumination less than 40 dB.

Parallel read out
Using a CCD array as a photosensitive element opens up new opportunities for parallel reading with high data rate. Mega-pixel CCD arrays with frame rate of several kHz provide data rates up to Gbit/s. The CCD-array-based on time delay integration (TDI) technology is capable of reading a low-intensity signal with data rates of about several tens of MHz. For average data density the corresponding data rate is 10 Mb/s.. Note that the mechanical velocity is 450 times less than in a DVD player. Standard demand for reading in DVD format SNR > 20 dB is satisfied even for velocity of 100 mm/s with corresponding data rate of 0.1 Gbit/s. The imaging of fluorescent marks provides the spatial resolution twice that for the reflected signal because of the non-coherent nature of fluorescence.

INDUSTRIAL PRODUCTION PROTOTYPES

Constellation 3D, Inc. has developed and proven the basic technology and will continue to develop fully functional prototypes of end-user products. With respect to each of the following products, the company will seek and establish joint ventures with strategic partners having an established market share and manufacturing capability in the relevant product market.

FMC Clearcard-Rom

The planned initial production model is a credit card ” sized ClearCard ROM with up to 20 layers, 400 MB/cm 2 data density and up to 10 GB capacity, twice the current single-sided DVD disc, but at a fraction of the cost and size. The design of the reader will be simple, with virtually no moving parts, making them resilient to all kinds of shocks. The potential number of applications for which these cards could be used is almost limitless”from e-books and home entertainment systems to e- books and archival and navigational systems. The ClearCard could also be used in many applications where CD/DVD discs are currently used. The cost of production of these cards is less than $10.

Note: Constellation 3D has recently confirmed in its labs the feasibility of production of a 50-layer ClearCard ROM with a storage capacity of 1 Terabyte and data transfer speeds of up to 1 Gigabyte/s. The card would be intended for use in HDTV, video and music-on- demand and other multimedia applications.



FMC Clearcard Recordable

The card is a compact version of the FMC ClearCard that enables the user to record the initial information to be stored. The planned initial production model is a credit card sized 10-layer disk with a 1 Gigabyte capacity. It is designed to fit into devices such as laptop and hand-held computers, digital cameras, cellular phones and video recorders and players, for which it will offer light weight, high capacity storage and quick access to data. The next generations of recordable cards will have nearly as much capacity read-only cards. For cameras and video players, the ClearCard Recordable will not only offer the same gains as for laptop and hand-held computers but also offer higher quality video. This technology will be ideal for downloading information from the Internet.

FMD ROM

This disc takes the CD-ROM and DV D-ROM concept to the next level. The planned initial production model is a 120-mm 10-layer disk with 140 Gigabyte capacity, compared to less than 18 Gigabytes for a maximum capacity DVD, giving it the capacity to store up to 20 h of compressed HDTV film viewing. As mentioned above, existing CD and DVD 120-mm disc and drive manufac-turing equipment will be adaptable with minimal re tooling to accommodate the new technology. The new FMD drives will also be backward compatible with (i.e. capable of reading) existing CD and DVD media. However, it is anticipated that the majority of users will, at an early stage, decide to take advantage of the much larger capacities and superior performance characteristics of the new FMD discs and make it their media of choice for future data storage applications.


FMD/ C Re”Writable

Re-writable optical memory carriers have recently been gaining attention within the optical memory community and provide the maximum amount of flexibility in the determination of data stored at any given time it is a fundamental requirement of hard disk drives in PCs. In between the two extreme approaches to storing memory, ROM and re-writable, are data storage applications where the user requires the flexibility of deciding the initial data to be stored on the media and then the certainty that the data will not later be erased or amended. The initial solution to the most effective data management is FMD/C RECORDABLE storage carriers of very significant capacity. In particular Constellation 3D intends to produce a credit card sized ClearCard TM - RECORDABLE with 4.7 GBytes capacity and costing under $1O,thereby providing users of handheld devices with a cost- effective solution to their Internet downloading and other data write- once needs. The next generation products will include genuinely rewritable layers based on the most recent development carried out by Constellation 3D.

Media Manufacturing Technology

The fluorescent media manufacturing process described here utilises many processes that are typical for CD and/or DVD manufacturing However, fluorescent media requires many proprietary polymers and compositions that were exclusively developed by Constellation 3D Inc the Company intends to make these materials available to media manufacturers through its selected industry affiliated partners. The media manufacturing process described in this article relies on well known optical disc replication process. Further developments related to increase of data storage capacity to the level of multihundreds of gigabytes per disc, will require adoption of other disc manufacturing technologies currently under internal development:

Pre-mastering and mastering process

Pre-mastering and mastering processes are very similar to those utilised by CD/DVD industry. However, certain modifications of the mastering process will be required (namely glass master and stamper preparation).

These modifications are mainly related to pit geometries that are designed to facilitate reliable pit replication and pit filling.

Replica manufacturing

Replica manufacturing involves preparation of circular substrates made of low birefringence plastic film (polycar-bonate, PMMA or other films with appropriate optical characteristics). Film thickness is between 25 to 30 res. prior to usage substrates are die or laser-cut to appropriate diameter (media dependent, see above). The prepared substrate is placed over radial bead of photo-polymer deposited onto a nickel matrix top surface (stamper). During the spinning process photopolymer evenly spreads between the stamper surface and the plastic substrate. Subsequently, UV curing hardens the photo-polymer and now the substrate can be separated from the top surface of the stamper. The substrate contains the precise pit geometry. The precision of pit replication exceeds quality of injection-moulded substrates (such as CDs or DVDs).

Pit filling

During pit filling, the fluorescent dye-polymer evenly s p reads over the entire replicaâ„¢s informational side by utilizing the spin-coating process (similarly to CD-R dye application) .After the dye-polymer is UV cured; a certain chemical bleaching process is applied to achieve the desired signal contrast ratio of pits and lands.

Replica inspection

Each replica is optically inspected to verify proper dye-polymer filling. Such inspection is achieved by observing the emitted light from the entire area of data pits by utilizing a CCD camera. At this stage each replica is optically inspected for various physical defects such scratches, inclusions, etc.

Layer bonding

Layers or replicas are centrally bonded onto an optical spacer (0.6-mm thick polycarbonate or PMMA substrate), by utilizing a capillary bonding method well known to the DVD industry. Since replicas are thin and thus more pliable, formation of air bubbles in the bonding layer is minimized. The requirements on centricity of informational layers are similar to DVD discs (or ±25 micrometer).

Disc decoration

After multiple replicas are bonded on the top of optical spacer (see above) an additional support/protection substrate is bonded on the stack top. These decorated elsewhere substrates are made of solid color inexpensive plastic materials.

Edge sealing

In order to prevent layer separation by physical contact, the disc outer edge is sealed with UV curable photo-polymers typically used for protection of CDs and DVDs.

SCOPE OF FMD

Companyâ„¢s Plans

Dell monitoring advancements in optical technology, and expects the cost and performance of CD-RW drives to become more competitive with the magnetic formats. Dell plans to offer CD-RW/DVD-ROM Combo drives when reasonably priced, reliable devices become available. These devices should eventually replace current CD-RW drive and offer convenience, large storage capacities that are backward- compatible with previous CD formats, and DVD-ROM readability. Dell expects DVD-RAM systems to be adopted by highend users, initially. RAMbo systems, when available, are expected to provide another step in the evolution to a universal RMSD providing a large-capacity drive capable of reading and writing to the most popular CD/DVD formats.

Dell is also monitoring the development of blue laser and FMD/FMC technologies for their potential applications with existing optical formats. The smaller wavelength of the blue laser may allow data density increases from three to four times the storage capacity of current optical discs. FMD technology could provide an eight-fold increase incurrent optical disc storage capacity, and a new, smaller card format could provide an attractive, high-capacity alternative to disc storage.



CONCLUSION

Most PC applications today require more removable storage capacity than a standard floppy disk provides. At best, floppy drives offer inconvenient and time-consuming data transport for large files and applications, and require numerous disks to accomplish the task. There are a number of other magnetic storage options available today, but none of them are an ideal successor to the floppy drive. Zip drives provide adequate storage for most data transactions, but the drives are limited by their lack of compatibility with floppy disks. Imation Super Disk drives provide acceptable storage space per disk, floppy disk compatibility, and system bootabiity, but have not become a universal standard.

Optical systems are becoming the PC storage devices most likely to replace the floppy drive standard. CDROMs already are the media of choice for software applications. Zip and Super Disk drives provide a good interim RMSD solution for recording requirements, and CD-RW drives will offer a more universal standard as their costs decrease. DVD-RAM and combination systems should provide high-end RMSD solutions using large-capacity DVD discs, and providing speed, durability, data availability, bootability, and backward compatibility to CDs. Current CD-ROM/DVD-ROM disc production processes will need relatively minor changes to incorporate fluorescent multilayer technology. An FMD requires slightly deeper grooves and data pits, filled with a proprietary fluorescent storage material, for each data layer of a multilayer disc. Initial claims for the ROM version describe a multilayer disc with a 140-GB storage capacity, equivalent to approximately 20 hours of compressed HDTV data. FMD drives could be made to read existing CD-ROM/DVD-ROM discs.

Future enhancements of multilayer fluorescent storage technologies, may contribute to this longevity with the potential to provide even greater increases in data densities and transfer rates.

REFERENCES

¢ c3D-consortium.com
¢ google.com
¢ computer PC magazines


CONTENTS

¢ INTRODUCTION 01
¢ WHY FMD? 03
¢ FMD ROM DISC AND DRIVE 04
¢ DIGITAL DATA STORAGE DEVELOPMENT 08
¢ STATUS OF DEVELOPMENT 13
¢ INDUSTRIAL PRODUCTION PROTOTYPE 23
¢ SCOPE OF FMD 28
¢ CONCLUSION 29
¢ REFERENCES 30




ACKNOWLEDGEMENT

I express my sincere gratitude to Dr. Agnisarman Namboodiri, Head of Department of Information Technology and Computer Science , for his guidance and support to shape this paper in a systematic way.

I am also greatly indebted to Mr. Saheer H.B. and Ms. S.S. Deepa, Department of IT for their valuable suggestions in the preparation of the paper.

In addition I would like to thank all staff members of IT department and all my friends of S7 IT for their suggestions and constrictive criticism.
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02-02-2010, 03:01 PM


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INTRODUCTION

Fluorescent Multilayer Disc (FMD) is an optical disc format It was developed by a company called constellation 3D (C3D). that uses fluorescent, rather than reflective materials to store data. Reflective disc formats (such as CD and DVD) have a practical limitation of about two layers, primarily due to interference, scatter, and inter-layer cross talk. However, the use of fluorescence allowed FMDs to operate according to the principles of 3D optical data storage and have up to 100 data layers. These extra layers potentially allowed FMDs to have capacities of up to a terabyte, while maintaining the same physical size of traditional optical discs.
It is an optical format similar in size and appearance to regular CD-ROMs and DVDs but with storage capacity up to 140GB. Production of these discs is easily done with slight modification to that of CDs and DVDs, its relatively cheaper.

submitted by
Monika Pratap

FMD Principle
Data is stored on multiple layers unlike CDs or DVDs where
single layers are used.
Recording, reading and storing is done with help of fluorescent
materials embedded in pits or groves in each of the layers.
The fluorescent material emits radiation when excited by an
external light source.
This allows the information to be decoded by the changes in the
intensity and color of the emitted radiation.
FMD Technology
FMD technology, each storage layer is coated with a transparent
fluorescent material.
When the laser beam hits a mark on a layer, fluorescent light is
emitted.
The light emitted by fluorescent light is incoherent, not being
affected by data pits or other marks in the media, and passes
through adjacent data layers unaltered.
Salient features
In FMD devices, emitted light is filtered before it reaches the drive's detector.
This reduces the effect of stray light and interference - only data-conveying fluorescent light is detected.
The signal quality of conventional optical reflection systems degrades rapidly when additional data layers are added.
The filtered, incoherent light of FMD and FMC technology offers the potential for storage mediums with up to 100 data layers.
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ABSTRACT
How do you boost a computer's memory, both in capacity and in speed The usual model for memory storage features a recording/reading device (a "read-write head," a "probe tip," a "stylus,") and a surface on which that device can make its impression. So it's not surprising that some of the most promising research in the memory industry features a simple modification of that paradigm. Instead of just one recording surface, researchers are now thinking of using up to 100 layers, and a corresponding number of recording/reading devices, to store ever-greater quantities of data.
When multiple layers of storage material are coated with fluorescent material, they turn intervening laser beams into fluorescent light. This fluorescent light is immune to corruption from intervening layers and other lasers. More specifically, each base layer is marked with a pattern of "pits." When this layer is coated with fluorescent material, the pits gather a greater thickness of fluorescent stuff. The contrast between pit-thickness and layer-thickness of fluorescent material results in a unique reading of stored data.
1. INTRODUCTION
Requirements for removable media storage devices (RMSDs) used with personal computers have changed significantly since the introduction of the floppy disk in 1971. At one time, desktop computers depended on floppy disks for all of their storage requirements. Even with the advent of multi Gigabyte hard drives and fast Internet connections, floppy disks and other RMSDs are still an integral part of most computer systems, providing:
Transport between computers for data files and software > Backup to preserve data from the hard disks.
A way to load the operating system software in the event of a hard-drive failure.
Some RMSD options available today are approaching the performance, capacity, and cost of hard-disk drives. Considerations for selecting an RMSD include capacity, speed, convenience, durability, data availability, and backward compatibility. Technology options used to read and write data include:
Magnetic formats that use magnetic particles and magnetic fields. > Optical formats that use laser light and optical sensors.
Magneto-optical and magneto-optical hybrids that use a combination of magnetic and optical properties to increase storage capacity.
2. REMOVABLE MEDIA STORAGE DEVICES (RMSDs)
Let us have a glance on the different RMSDs.
2.1 Floppy Disk
Floppy disk drives provide faster data access because they access data randomly. Floppy drives provide an average data access speed of less than 100 milliseconds (ms).
The 1.44-MB, 3.5-inch iloppy is useful for storing and backing up small data files, can be used to boot computer systems, and has been the standard for data interchange between PCs. However it provides only a fraction of the storage capacity required for many files and most software programs in use today. Storing data on floppy drives also i; slow. Data transfer rates average around 0.06 MB/sec.
2.2 Optical Formats
Optical RMSD formats use a laser light source to read and/or write digital data to disc. CD and DVD are two major optical formats. CDs and DVDs have similar compositions consisting of a label, a protective layer, a reflective layer (aluminum, silver, or gold), a digital-data layer molded in polycarbonate, and a thick polycarbonate bottom layer
Label layer
layer
Optical Disk Composition
CD formats include:
¦ Compact disc-read only memory (CD-ROM)
¦ Compact disc-recordable (CD-R)
¦ Compact disc-rewritable (CD-RW)
DVD formats include:
* Digital versatile disc-read only memory (DVD-ROM)
¦ Digital versatile disc-recordable (DVD-R) DVD-RAM (rewritable)
¦ Digital versatile disc-rewritable (DVD-RW)
¦ +RW (rewritable)
2.3 CD-ROM
CD-ROM Standard was established in 1984.They quickly evolved into a low cost digital storage option because of CD-audio industry
Data bits are permanently stored on a CD as a spiral track of physically molded pits in the surface of a plastic data layer that is coated with reflective aluminum. Smooth areas surrounding pits are called lands. CDs are extremely durable because the optical pickup (laser light source, lenses and optical elements, photoelectric sensors, and amplifiers) never touches the disc. Because data is read through the thick bottom layer, most scratches and dust on the disc surface are out of focus, so they do not interfere with the reading process.
One CD-ROM (650-700 MB) storage capacity can store data from more than 450 floppy disks. Data access rate ranges from 80 to 120 ins. Data transfer rates are approximately 6 MB/sec.
2.4 DVD-ROM
The DVD-ROM standard, introduced in 1995 came over as a result of a DVD consortium. Like CD drives, DVD drives read data through the disc substrate reducing interferences from surface dust and scratches. However DVD-ROM technology provides seven times the storage capacity of CDs and accomplishes most of this increase by advancing the technology used for CD systems. The distance between recording tracks is les than half that is used for CDs. The pit size also is less than half that of CDs, which requires a reduced laser wavelength read the smaller sized pits. These features alone give DVD-ROM discs 4.5 times the storage capacity of CDs.
DVD drives can also store on both sides of the disc; manufacturers deliver the two-sided structure by bonding two thinner substrates together, providing the potential to double a DVD's storage capacity. Single sided DVD discs have the two fused substrates, but only one side contains data.
In a DVD, storage of data in the data layers can be:
Single-sided, single layer (4.7 GB)
Double-sided, single layer (9.4 GB)
Single-sided, double layer (8.5 GB)
Double-sided, double layer (17 GB)
Siiigle-sidea. single Inyei (4.TGB) I)oub,e.si(le(l Sinžle (9.4 GB)
T0.6mm I
HI Substrate Q Lacquer
Reflective Layer
Figure: DVD Data Storage Versions
2.5 DVD-R
DVD-R drives were introduced in 1997 to provide write-once capability on DVD-R discs used for producing disc masters in software development and for multimedia post-production. This technology sometimes referred to as DVD-R for authoring, is limited to niche applications because drives and media are expensive.
DVD-R discs employ a photosensitive dye technology similar to CD-R media. At 3.95 GB per side, the first DVD-R discs provided a little less storage capacity than DVD-ROM discs. That capacity has now been extended to the 4.7-GB capacity of DVD-ROM discs. The IX DVD-R data transfer rate is 1.3 MB/sec. Most DVD-ROM drives and DVD video players read DVD-R discs. Slightly modified DVD-R drives and discs have recently become available for general use.
2.6 DVD-RAM
DVD-RAM (rewritable) drives were introduced in 1998. DVD-RAM devices use a phase change technology combined with some embossed land/pit features. Employing a format termed "land groove", data is recorded in the grooves formed on the disc and on the land between the grooves. The initial disc capacity was
2.6 GB per side, but a 4.7 GB- per-side version is now available.
The 4.7-GB DVD-RAM discs come in cartridges that protect the medium from handling damage, such as fingerprints and scratches. A single-sided disc is expected to be removable from the cartridge so it can also be played in DVD-ROM drives that support DVD-RAM. The double-sided disc, providing 4.7GB of storage capacity per side, is not removable from the cartridge.
Each DVD-RAM disc is reported to handle more than 100,000 rewrites. DVD-RAM is specifically designed for PC data storage; DVD-RAM discs use a storage structure based in sectors, instead of the spiral groove structure used for CD data storage. This sector storage is similar to the storage structure used by hard drives. Sector storage results in faster random data access speed.
Because of their high cost relative to CD-RW technology, current consumer-oriented DVD-RAM drives and media are not a popular choice for PC applications. Slow adoption of DVD-RAM reading capability in DVD-ROM drives has also limited DVD-RAM market acceptance.
2.7 DVD-RVV
The DVD-RW drive format is similar to the DVD-R format, but offers rewritability using a phase-change recording layer that is comparable to the phase-change layer used for CD-RW. DVD-RW is intended for consumer video (non -PC) use, but PC applications are also expected for this technology. The first DVD-RW drives based on this format, which also recorded DVD-R discs, were introduced in early 2001.
2.8 +RW
Sony and Philips were founding members of the DVD consortium, but broke away to introduce the DVD+RW (now called +RW) phase change, rewritable technology in 1997. Discs can be written approximately 1000 times, which makes them a good option for video recording, but not optimal for data storage. +RW technology's strongest feature is its backward compatibility with DVD-ROM drives and DVD video players.
2.9 Magneto-Optical Formats
Magneto-optical (MO) technology combines he strengths of magnetic and optical technologies by using a laser to read data and the combination of a laser and magnetic field to write data. The top (label side) of the disk is exposed to a magnetic field to write data, and a laser light source targets the data layer through the bottom substrate to read data.
There are 3.5- and 5.5-inch disk formats that contain a magnetic alloy layer. Magnetic particles in the alloy are very stable and resist changing polarity at room temperature. Data bits re recorded on this magnetic layer by heating it with a focused laser beam in the presence of magnetic field. Changes in the magnetic orientation of the data bits along a track represents Os and Is much like on hard disks and other magnetic media. The magnetic layer also changes the rotation or polarization of reflected laser light depending on the 0 or 1 polarity of the magnetic bits. This property called the "Kerr Effect" and is used to read the data. MO systems also increase the data bits vertically rather than horizontally.
The 3.5-inch disks are available in 128-, 230-, and 640-MB storage capacities. The 5.25-inch disks come in 650-MB and 1.3-, 2.6-, and 5.2-GB sizes. A 9.1 -GB size is expected soon. At less than 25ms, data access times faster than the average 100ms of phase change CD and DVD technologies. MO drives are widely used in Japan for general-purpose storage, similar to the way Zip drives are used in the U.S. Outside of Japan; applications for MO drives typically have been in niche markets for Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), document imaging, and high-capacity archives.
2.10 Holographic Data Storage
Researchers promise huge increases in data storage density and data transfer rates with holographic data storage. Unlike methods that store data two-dimensionally on surface layers of media, holographic data is stored volumetrically, or three-dimensionally, throughout the thickness of the media. Additionally, data is stored .and accessed in a page format capable of containing approximately 1 million data bits at a time.
Estimates for this technology predict a storage potential of 200 GB on one 5.25-inch removable disc. This capacity is more than 40 4.7-GB DVD discs. Data transfer rates are estimated at less than 30 MB/sec for a page format containing 1 million data bits. Holographic storage could also be developed in non disc form in any 3D shape.
The majority of holographic data storage research has been funded by the U.S. government through the holographic data storage system and photo refractive information storage consortia. To date, only two companies Lucent Technologies and Imation Corporation, have committed to investing in commercialization of the media. If the technology proves to be commercially feasible, the first systems most likely will be developed for enterprise storage applications. Small robust, holographic storage devices, for use as PC drives, are probably many years from production.
Fluorescent Multi-layer Memory
~~3. FLUORESCENT MULTI-LAYER MEMORY^
Fluorescent multilayer disc (FMD) and fluorescent multilayer card (FMC) are 3D optical storage technologies being developed by C3D, Inc. A disc or card data pit, tilled with a fluorescent material emits fluorescent light when a laser light source is focused on the pit. The emitted light passes through the adjacent data layers unaltered, and is filtered before it reaches the drive's detector, which reduces the effect of stray light and interferences-only data-conveying fluorescent light is detected.
The signal quality of conventional optical reflection system degrades rapidly when additional data layers are added; current research indicates only a few layers are feasible. DVD's two layer data format is an implementation of this research. The filtered, incoherent light of FMD and FMC technology offers the potential for volumetric storage with up to 100 data layers
A FMD requires slightly deeper grooves and data pits, filled with a proprietary fluorescent storage material, for each data layer of a multilayer disc. C3D claims that current CD-ROM/DVD-ROM disc production processes will require relatively minor changes to incorporate fluorescent multilayer technology. High-yield production would be the greatest challenge for this integration process. Initial claims for the ROM version describe a 30-layer disc with a 140-GB storage capacity, equivalent to approximately 20 hours of compressed HDTV data. FMD drives could be made to read existing CD-DVD-ROM discs.
When multiple layers of storage material are coated with fluorescent material, they turn intervening laser beams into fluorescent light. This fluorescent light is immune to corruption from intervening layers and other lasers. More specifically, each base layer is marked with a pattern of "pits." When this layer is coated with fluorescent material, the pits gather a greater thickness of fluorescent stuff. The contrast between pit-thickness and layer-thickness of fluorescent material results in a unique reading of stored data.
This fluorescent material is currently made of polymers that are owned by Constellation 3D. The company intends to market these polymers to other firms, as well as produce the 3D data-storage systems themselves. It looks to be a huge score for the firm. In a field where increasing storage capacities mean greater danger of data corruption, Constellation 3D has found a back door to long-term, high-capacity
Fluorescent Multi-layer Memory
memory. Research has shown that systems using fluorescent material resist corruption much longer than naked systems. And researchers have recently posited devices containing as many as 100 layers separated by fluorescent coatings -- shattering earlier forecasts of feasible storage capacities.
Not only will storage capacities be exponentially increased; the technology is also potentially much faster at accessing information than are single-layer devices. Multiple layers can be read simultaneously, as can different patches of the same layer. This is an important step towards commercializing the product because, up to this point, technologies have tended to focus on either capacity or speed, failing to incorporate both.
Ease of upgrading is another strategic advantage to multilayer fluorescent technology. Existing CD and DVD manufacturing lines can be modified to FMD standards without altering their essential structure. Most systems would only require a few extra steps to deposit coatings with fluorescent materials.
As to the fluorescent material itself, there are a few criteria that need to be met. Most generally, the fluorescent material must be compatible with the layer it's coating, and the wavelength it absorbs must be identical to that used in the drive. It must be a reasonably stable material, although its response time should not be greater than 1 nanosecond. With its refraction index similar to that of its polycarbonate sub layer, the fluorescent material must have high conversion efficiency. Finally, the beam that gets reflected through the fluorescent material should be wavelength-shifted by at least 50nm so that the two beams do not get confused within the system.
3.1 FMD-ROM: operating principle
On the picture you can see how a FMD-ROM looks like.
You can see that a disc is transparent. But where is a reflective layer like on CD and DVD discs The matter is that this technology doesn't need it. Let's consider FM disc in detail.
In optical discs such as CD, DVD and MI the process of reading is implemented the following way. A beam of a semi-conducting laser gets on the surface of an informational layer and then reflects from aluminum (or any other metallic) layer and fixed with a detector-receiver. In FMD there is no reflected laser beam: when a laser beam reaches an informational layer the latter starts radiating.
The principle of operation of FM-discs is based on a phenomenon of photochromism. Some years ago Russian chemists discovered a stable organic
material a "stable photochrome" which when acted upon by a laser beam obtains fluorescent properties.
The matter is that an informational element of FM-disc (photochrome) can change its physical properties (such as color and presence of fluorescence) under influence of a laser of a definite power and wavelength. Initially photochrome doesn't possess fluorescent properties. When switching on a laser a photochemical reaction starts what causes fluorescent properties to appear. When reading, this matter becomes excited again but with a laser of lower power. The fluorescence is caught up by a photo-receiver and is fixed as a value "1".
Besides, according to the company there will be no worsening of the photochrome state with the time.
comparison
REFLECTIVE DISK FLUORESCENT DISK
I Filter
Excited photochrome radiates shifting the spectrum of falling light to the red color side within 30-50 nm what allows differing laser signal from the light from the disc.
Note that this technology allows preventing a problem of multiple inference between layers since the reflected light is not coherent; it passes through layers without any difficulties and is easily defined by a receiver. Let's talk about it a bit in depth.
In usual optical discs (CD/DVD) with increasing number of informational layers a signal gets worse. It's explained by the fact that these technologies use a reflected signal; it means that there is necessity in mirror surfaces. That's why in DVD technology an external layer is made to be semitransparent in order to allow a laser to reach an internal one.
And a signal while passing an external layer leaves a part of its energy because of reflecting. Signals reflected from both layers interfere because of their coherence; it results in losses of useful signal. Increasing number of layers aggravates an effect of multiple interference between the layers what makes reading more complicated. The problem can be solved by improving detector-receivers, but it is possible only in laboratory. In case of fluorescent discs the quality of the signal gets worse much slower with increasing number of layers. According to FMD-ROM developers, even with a hundred layers a useful signal will be acceptable.
3.2 FM-disc
As you can see in the picture a disc consists of several plastic (polycarbonate) layers connected to each other. A layer contains surface structures (pits) which are filled with fluorescent material. When reading a laser focuses on a certain layer and excites its fluorescent elements, and then this radiation is caught by a photo detector.
The developers state that with a blue laser (480 nm) it's possible to increase record density up to tens Terabyte on one FM disc.
Another interesting feature is parallel reading. If we record a sequence of bits not along a track but deep into layers we can increase speed of data access. That's why such disc is called "3-dimensional".
3.3 FM disc production
Many stages of their production are put on the basis of CD and DVD manufacture. However, some alterations are to be made here. In particular, they concern form of surface structures and methods of filling with fluorescent material. Besides, there is no technology of sputtering of aluminum layer what reduces the number of steps.
Mastering process is very similar to that of CD/DVD. A few words on a process of manufacturing CD discs.
As a storage device they use a glass plate covered with a thin photoresistive layer. A laser beam, intensity of which is modulated with digital information, gets into photoresist causing markings that correspond to bits of digital code. After that the photoresist is developed and covered with a metallic layer. This Master-copy after recording contains digital information in the form of pits. Then they make an exact negative copy by a galvanic way which later serves as a press-matrix. This negative can already be used for CD manufacture. But in order to save this single matrix they produce several intermediate copies (negative), and then several press-matrix (the same way) which serve for stamping CDs. After recording of data on an informational surface in vacuum a thin layer of aluminum is sputtered. Outside, the metallic layer is lacquered in order to prevent mechanical damage.
In FMD technology an exact copy of pit is of vital importance since later it's filled with fluorescent material. That's why these two technologies differ. Here, a master-copy is a nickel matrix (a stamp). It is a negative copy, like in CD-technology.
A FM disc consists of several layers that's why the process contains several steps: informational layers are produced separately and then they are combined together.
Technological process of FM discs is divided into two types.
Fluorescent Multi-layer Memory
In the first one there used a method of hot stamping. Each layer is reached by pressing of polycarbonate layer with two stamps (Master-copies) at high temperature. So we receive one layer with two informational sides. Then, pits starts being filled with fluorescent material. And when it becomes hard the informational layers are pressed.
In the picture you can see a structure of a 7-layer disc produced according to the described method.
Seven layer FM disc
The second method uses a process of photopolymerization when a multiple disc is 'reached by stacking of discs one after another which are made from thin informational layers.
Manufacture of one informational layer lies in manufacture of plastic film with definite optical characteristics. The film is 25 to 30 micron in width. The film which will get information soon is either stamped or cut out with a laser. After that the film is installed on an external surface of a nickel matrix that carries a negative copy of produced informational layer. While rotating, photopolymer matter is evenly brought in the space between stamp surface and plastic film. Later, when the photopolymer matter becomes hard the film gets detached from the stamp surface. The base plate now contains pits of definite geometry. A pit's geometry is better in terms of quality than that received when manufacturing matrices for CD or DVD since those technologies use a process of stamping of pits. When a layer with the required position of pits is ready, they are fdled with fluorescent material (it covers evenly the whole informational side). After that the surface is processed chemically in order to reach necessary contrast of pits and flats. Then, in order to check the copy for different defects, photoelements get excited and the whole picture is analyzed with the help of CCD cameras. After that the layers are "stuck" to the base plate 0.6 mm in width. And all this is covered with a protective layer which can be used for graphics decoration. In order to prevent a physical contact with informational layers on the edge of the disc this area is fdled as well with polymeric material, like in CD or DVD technologies.
3.4 FM read devices
The developers say that the drives intended for FM discs will easily understand CD and DVD formats. In structure the drives are similar to CD/DVD ones for example in such parameters as laser, optics, servodrive, tracking and focusing system, different controllers. There appear only systems that can catch and discern fluorescence, and a service in choosing an informational layer.
3.5 Recording on FMD-ROM
It uses a technology WORM (Write Once Read many). For manufacturing FMD WORM (re writable) a different fluorescent material is used. A technology of manufacturing these discs will be the same as for FMD ROM except the fact that they will use another fluorescent material which will be able to change the state under the influence of a laser. And when recording you should follow two rules: ¦ Sufficient power of a laser in order to provide an element with fluorescent
properties.
Threshold power of laser should be used for recording (in order to change fluorescent properties of the material) and for reading must be used less power.
Besides, it's very important to choose a recording method. The FMD developers offer
two record principles.
The first principle (thermal) implies usage of material which possesses
fluorescent properties from the beginning (logical one). And when recording those
segments which are thermally acted upon with a laser lose these properties (logical
zero).
The second principle (chemical) means usage of a material that doesn't possess fluorescent properties form the beginning. When acting upon with a laser a ¦photochemical reaction starts, and the materia! gets fluorescent properties. There, a low-power laser is enough, or even a usual LED. With the latter (LED matrix) there is possible a simultaneous record of the whole array of information.
"Record devices don't differ much from read ones. The only difference lies in a bit different laser form allowing both reading and writing. Besides, we should note that it's possible to combine WORM and ROM on one storage device! For example, imagine a 20-layer disc with 10 layers already recorded and 10 left for a user.
The company C3D has released rewritable FM discs. The record principle is practically the same as in CD-RW technology except for the fact that there it isn't necessary to control reflective ability of a layer - there is enough to convert fluorescent material from one state (absence of fluorescence) into the other (presence of .fluorescence). For example, the whole layer of a FM disc will be covered with a fluorescent material which initially doesn't possess fluorescent properties (logical zero) and when recording a logical one a low-power laser excites a photochemical reaction in the required place. Erasure will be done with the help of a more powerful laser. An advantage of this technology is that the fluorescent material is much more resistant to phase transformations than that used in CD-RW discs that's why you can rewrite it much more times.
4. STATUS OF DEVELOPMENT
Constellation 3D's Fluorescent Multilayer technology enables the production, in a wide variety of form factors, of storage media satisfying these criteria
4.1 Media
The FMD/C media consist of several plastic (polycarbonate) substrates, bonded together. The substrates contain surface structures ("pits") that are filled with a proprietary fluorescent storage material. A major design goal in the development of CD/DVD replacements using this technology was to allow a simple and cost effective upgrade for existing manufacturers of optical devices. FMD technology enables the use, with only relatively minor changes (such as impregnation with fluorescent materials), of existing components and processes from high volume products such as CDs/DVDs, and avoids the need for new infrastructure for media and drive production. The number of process steps per layer is actually reduced, because a reflective metallic layer is not required. For the individual layer of a multilayer disc, metal stampers containing the digital content are produced in a mastering process that is similar to CD or DVD processes. For FMD/C, two replication processes have been developed:
Hot-Embossing:
In this process, thin sheets of polycarbonate are embossed on both sides .with the metal stampers at elevated temperatures. The embossed pits are then filled with the fluorescent dye. After the dye is cured, the individual sheets are bonded together under pressure, resulting in a storage media having multiple layers.
Photo-Polymerization (2P) Process:
In this method, layers are replicated one after the other by forming of "thin replicas". This technology has been demonstrated for up to ten layers.
4.2 Fluorescent Material
Perhaps the most critical component of the storage media is the fluorescent material that converts the incident (incoherent) laser light into incoherent fluorescent light. The materials and associated drives for read-only cards & discs (ROM) are currently the most mature FM technology. Recordable materials and associated drives have also been developed and demonstrated, and improvement of this FM technology continues. FMD/C write/read technology based on proprietary photochromic substances has been demonstrated in Constellation 3D's laboratories during write/ read/erase/re¬-write experiments
4.3 FMD/C ROM (Read Only) Devices
There are several requirements for the fluorescent materials:
1. The fluorescent ROM material has to be compatible with the substrate material
2. The absorption wavelength should be the same wavelength as commercially
available, low cost semiconductor lasers used in CD players
3. The emitted fluorescent light should be wavelength-shifted by at least 50nm, to allow easy separation of the incident and signal light
4. The material should have high conversion efficiency
5. The material should have the refraction index close to the one of the polycarbonate
6. The material should stay stable over a reasonable time
7. Fast response - lnsec
Light-sensitive material:
The photo-polymer composition (PPC) - is a mixture of monomers and oligomers with photoinitiator, which initiates polymerization process under radiation in the certain spectrum range. PPC serves as substrate for the data carrier, oxazine-1, methylene blue, methylene violet and other red dyes serve as the photo-initiator
Pit filling process: .
The working surface of a polycarbonate disc is a plane with pits - cavities 0,5um in size, located in a certain order. Such micro relief can be filled with liquid monomeric or oligomeric substances that turn into hard polymer substances when subjected to UV light. The substances fill the pits and overflow to form a thicker layer on the media surface. The ratio of layer thickness in pit to its thickness on the surface makes the contrast. One of the main tasks of confronting the scientists in developing the process of filling the pits, creating the overflow and choosing the material, was to find the combination of these that provided the largest such contrast.
4.4 FMD/C Recordable (Write Once Read Many) Devices
In addition to the requirements for ROM media, RECORDABLE media require the following:
A writing process where the writing light is able to turn on or off the fluorescence.
A threshold level above which the fluorescent material is changed by the power level of the write, and below which the material is unchanged during any subsequent read-out. Currently 2 techniques have been developed: Thermal Bleaching:
In this technique the material is initially fluorescent. The incident write light heats the material, destroying the fluorescence. The write parameters are similar to CD/R recording and the standard optical writing 15mW laser is well suited for providing CD-R equivalent data writing rates. Materials suitable for applying this technique for use with red, green and blue laser wavelengths have been developed. ¦Photochemical Reaction:
Materials of this class are initially not fluorescent, and the write light initiates photo-chemical reactions, thereby creating fluorescence. The highly non-linear process associated with this reaction causes an effective threshold. Because no heating is involved, the required write power is low, allowing even light emitting diodes (LED arrays) to be used. With LED arrays, pages of information can be written simultaneously, thereby additionally enabling card applications. Current materials are sensitive to green and violet wavelengths.
4.5 FMC "CLEARCARD" Reader
The block diagram above shows the device for reading data from a Fluorescent Multi-Layer Card (FMC)-"ClearCard". A semiconductor laser produces a beam, which is then focused on a selected layer ofthe card. A cylindrical lens forms a 500x2um line, which by means of a scanning mirror scans across a page area of the card. The induced fluorescent light is imaged to a CCD array. A "frame grabber" receives data from the CCD. In the subsequent image processing step the image is aligned, distortions are
CteuCaixl \ '

i
I
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i
corrected, the image is "thresholded" and digital data is. generated
CleaiCard system
5.25" FHFonn Factor
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^\ steppe^ l*t2--:
TocuT Enor
-0 una
Data
CCD
Auto
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Frnine Grabber linage Processing
4.6 FMD Disc Drive
The drives have most components in common with CD/DVD systems: Laser, beam-forming optics, spindle, tracking / focusing actuators, control electronics, data channel, data interface. The only additional components are filters to separate the fluorescent light from laser light, and an optical element to correct for different optical path length in the storage medium, depending on the selected layer. Modifications in the electronics include detector circuit with higher sensitivity and the addition of servo electronics to address different layers within the multi-layer disc. A schematic diagram of a FMD drive is shown.
DISK
SPINDLE
LENS SPHERICAL / ABBRECAT10N DICHROMATIC
, CORRECTOR /M„¢-
ACTUATOR. TRACKING FOCUSSING
FIL
LASER DRIVER
I
! LASER
PRE SIGNAL
AMP | PROS
DATA CONTROL
FMD DISK DRIVE
5. Industrial Production Prototypes
Constellation 3D, Inc. has developed and proven the basic technology and will continue to develop fully functional prototypes of end-user products. With respect to each of the following products, the company will seek and establish joint ventures with strategic partners having an established market share and manufacturing capability in the relevant product market.
5.1 FMC ClearCard ROM
The planned initial production model is a credit card-sized ClearCard -ROM with up to 20 layers, 400 MB/cm2 data density and up to 10GB capacity* - twice current single-sided DVD disc, but at a fraction of the cost and size. The design of the reader will be simple, with virtually no moving parts, making them resilient to all kinds of shocks. The potential number of applications for which these cards could be used are almost limitless - from e-books and home entertainment systems to e-books and archival and navigational systems. The ClearCard could also be used in many applications where a CD/DVD discs are currently used. The cost of production of these cards is less than $10.
Constellation 3D has recently confirmed in its labs the feasibility of production of a 50.-layer.ClearCard ROM with a storage capacity of 1 Terabyte and data transfer speeds of up to 1 Gigabit/second. The card would be intended for use in HDTV, Video & Music-on-demand and other multimedia applications.
5.2 FMC ClearCard RECORDABLE
The card is a compact version of the FMC ClearCard that enables the user to record the initial information to be stored. The planned initial production model is a credit card sized 10-layer disk with a 1 Gigabyte capacity. It is designed to fit into devices such as laptop and hand-held computers, digital cameras, cellular phones and video recorders and players, for which it will offer light weight, high capacity storage and quick access to data. Next generations of recordable cards will have nearly as much capacity read only cards. For cameras and video players, the ClearCard-RECORDABLE will not only offer the same gains as for laptop and hand-held computers but also offer higher quality video. This technology will be ideal for downloading information from the Internet.
portable
5.3 FMD ROM
This disc takes the CD-ROM & DVD-ROM concept to the next level. The planned initial production model is a 120mm 10-layer disk with 140 Gigabyte capacity - vs. less than 18 Gigabytes for a maximum capacity DVD - giving it the capacity to store up to 20 hours of compressed HDTV film viewing. As mentioned above, existing CD & DVD 120mm disc and drive manufacturing equipment will be adaptable with minimal re-tooling to accommodate the new technology. The new FMD drives will also be backward compatible with (i.e., capable of reading) existing CD & DVD media.
However, it is anticipated that the majority of users will at an early stage decide to take advantage of the much larger capacities and superior performance characteristics of the new FMD discs and make it their media of choice for future data storage applications.
5.4 FMD/C Re-Writable
Re-Writable optical memory carriers have been recently been gaining attention within the optical memory community and provides the maximum amount of flexibility in the determination of data stored at any given time - it is a fundamental requirement of hard disk drives in PCs. In between the two extreme approaches to storing memory, ROM and Re-Writable, are data storage applications where the user requires the flexibility of deciding the initial data to be stored on the media and then the certainty that the data will not later be erased or amended. The initial solution to the most effective data management is FMD/C RECORDABLE storage carriers of very significant capacity. In particular Constellation 3D intends to produce a credit card sized ClearCard -RECORDABLE with 4.7 GBytes capacity and costing under $10, thereby providing users of hand held devices with a cost effective solution to their Internet downloading and other data write-once needs. The next generation products will include genuinely re-writable layers based on most recent development carried out by Constellation 3D.
5.5 Media Manufacturing Technology
Fluorescent media manufacturing process described here utilizes many processes that are typical for CD and/or DVD manufacturing. However, fluorescent media requires many proprietary polymers and compositions that were exclusively developed by Constellation 3D Inc. Company intends to make these materials available to media manufacturers through its selected industry affdiated partners. Media manufacturing process described in this document relies on well known optical disc replication process. Further developments related to increase of data storage capacity to the level of multi-hundreds of gigabytes per disc, will require adoption of other disc manufacturing technologies currently under internal development:
¢ Pre-mastering and mastering process Pre-mastering and mastering processes are very similar to those utilized by CD/DVD industry. However, certain modifications of mastering process will be required (namely glass master and stamper preparation). These modifications are mainly related to pit geometries that are designed to facilitate reliable pit replication and pit filling
¢ Replica manufacturing
Replica manufacturing involves preparation of circular substrates made of low birefringence plastic film (polycarbonate, PMMA or other films with appropriate optical characteristics). Film thickness is between 25 to 30 microns. Prior to usage, substrates are die or laser cut to appropriate diameter (media dependent, see above). Prepared substrate is placed over radial bead of photo-polymer deposited onto nickel matrix top surface (stamper). During spinning process photo-polymer evenly spreads between stamper surface and plastic substrate. Subsequently, UV curing hardens photo¬polymer and now substrate can be separated from top surface of stamper. Substrate contains precise pit geometry. Precision of pit replication exceeds quality of injection-molded substrates (such as CDs or DVDs).
¢ Pit filling
During pit filling, fluorescent dye-polymer evenly spreads over entire replica's informational side by utilizing of spin-coating process (similarly to CD-R dye application). After dye-polymer is UV cured, certain chemical bleaching process is applied to achieve the desired signal contrast ratio of pits and lands
¢ Replica inspection
Each replica is optically inspected to verify proper dye-polymer filling of pits. Such inspection is achieved by observing of emitted light from entire area of data pits by utilizing of CCD camera. At this stage replica is optically inspected for various physical defects such scratches, inclusions and alike
¢ Layer bonding
Layers or replicas are centrally bonded onto optical spacer (0.6 mm thick polycarbonate or PMMA substrate), by utilizing capillary bonding method well known to DVD industry. Since replicas are thin and thus more pliable, formation of air bubbles in the bonding layer is minimized. Requirements to centricity of informational layers are similar to DVD discs (or +/- 25 micron).
¢ Disc decoration
After multiple replicas are bonded on the top of optical spacer (see above), additional Support/protection substrate is bonded on the stack top. These decorated elsewhere substrates are made of solid color inexpensive plastic materials
Fluorescent Multi-layer Memory ¢ Edge sealing
In order to prevent layer separation by physical contact, disc otiter edge is sealed with UV curable photo-polymers typically used for protection of CDs and DVDs.
5.6 FMD/C Advantages
The main advantages of multilayer fluorescent read out are:
1. The multi-layer system is optically transparent and homogeneous.
2. Low absorption in each layer.
3. No absorption for the emitted signal fluorescent light.
4. Lower than CD/DVD sensitivity to imperfections in media and drives. The
fluorescent technique does not depend on interference effects and requires less stringent
manufacturing tolerances for media and drives.
5. The emitted fluorescent light from any given layer is non-coherent, eliminating the problem of parasite interference.
6. The limited lateral spatial resolution for this system is twice that for coherent light based systems (e.g. current CD/DVD reflective systems). In the case of FMD/C, this two-fold improvement over three (3) dimensions, results in an eight-fold improvement in achievable data density.
7. FMD technology is compatible with current CD and DVD formats, having the capacity to handle the same data rates over each of its layers.
The above qualities make FMC unique in its technological capability to facilitate production of a multilayer optical card” ClearCard, in any form factor including postage stamp sized SmartMedia, credit card sized ClearCard, or otherwise. The capacity and speed of reading from these cards can be enormous. For instance, with the level of existing technology ClearCard of 16 cm2 of area with 50 layers can furnish consumers with 1 terabyte capacity and, through parallel access to all its layers, allow over 1 gigabit/sec speed of reading. Another major advantage, for both cards and discs using the technology, is the ability to read data on every layer of the media in parallel, thereby allowing the potential of much grater data transfer rates compared with single layer media. This can be combined with parallel reading from multiple sectors of the same layer to increase data speeds still further, producing 3-dimensional data transfer.
Here is a table demonstrating one of the project and implimentations of C3D:50 GB disc (12 layers):
Parameter CD DVD FMD
Disc diameter, mm 120 120 130
Capacity, GBytes -,.64 17,4 50,8
Number of layers i i 2 12
Distance between layers, micron - 40 25±5
Total width of layers, micron 0,11 2 275
Optical system wavelength, nm 780 635-650 532
Distance between tracks, micron 1,6 0,74 0,8
6ž Conclusion
Constellation 3D's fluorescent multilayer optical data storage technology can be utilized to produce compact, removable, inexpensive, rugged, ultra-high capacity data storage devices, having data transfer speeds in excess of lGbit/sec. The company wishes to maintain its focus on research and development in the field of fluorescent multilayer optical storage, with the intention of continually expanding the limits and capabilities of this technology. Having successfully demonstrated prototype multilayer cards and discs incorporating FMC/D technology, the way is now open - through joint ventures with industry leaders to commence industrial production of these devices and take them into the mainstream.
7, FUTURE SCOPE
Dell monitoring advancements in optical technology and expects the cost and performance of CD-RW drives become more competitive with the magnetic formats. Dell plan to offer CD-RW/DVD ROM Combo Drives when reasonably priced. Reliable devices become available. These devices should eventually replace current CD-RW drive and offer convenience, large storage capacity that are backward compatible with previous CD formats, and DVD ROM readability. Dell expects DVD-RAM systems to be adopted by high end users initially. Ram bo systems when available are expected to provide another system in a evolution to a universal RMSD providing a larger capacity drive capable of reading and writing to the most popular CD, DVD format.
Dell is monitoring the development of Blue laser and FMD/FMC technologies for their potential application with existing optical formats. The smaller wavelength of the blue laser may allow data density increase from 3 to 4 times the storage capacity of current optical storage device and a new smaller card format could provide an attractive, high capacity alternative to disk storage. By adding an extra layer and advantages of blue laser second and third generation of disk will be produced of capacity 1000GB.
Bibliography
[l].Ingolf Sander " White Paper on Fluorescent Multilayer Optical Data Storage ",
Constellation 3D, NY, USA [2]. vvww.us.net [3]. pcstats.com [4]. digit-life.com [5].dell.com [6]. computer.org
CONTENTS
Page
1. INTRODUCTION 01
2. REMOVABLE MEDIA STORAGE DEVICES 02
2.1 Floppy Disk 02
2.2 Optical Formats 02
2.3 CD-ROM 03
2.4 DVD-ROM 03
2.5 DVD-R 04
2.6 DVD-RAM 05
2.7 DVD-RW 05
2.8 +RW 06
2.9 Magneto-Optical Formats 06
2.10 Holographic Data Storage 07
3. FLUORESCENT MULTI-LAYER MEMORY 08
3.1 FMD-ROM: operating principle 10
3.2 FM-disc 12
3.3 FM disc production 13 3.4.FM read devices 15
3.5 Recording on FMD-ROM 15
4. STATUS OF DEVELOPMENT 17
4.1 Media 17
4.2 Fluorescent Material 17
4.3 FMD/C ROM (Read Only) Devices 18
4.4 FMD/C Recordable (Write Once Read Many) Devices 19 . 4.5 FMC "CLEARCARD" READER 19
4.6 FMD DISC DRIVE 20
5. INDUSTRIAL PRODUCTION PROTOTYPES 22
5.1 EMC ClearCard ROM 22
5.2 FMC ClearCard RECORDABLE 22
5.3 FMD ROM 23
5.4 FMD/C Re-Writable 24
5.5 Media Manufacturing Technology 24
5.6 FMD/C Advantages 26
6. CONCLUSION 28
7. FUTURE SCOPE 29
8. BIBLIOGRAPHY 30
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ABSTRACT
The growth in demand for digital storage capacity exceeds 60% per annum. Facilities such as storage area networks, data warehouses, supercomputers and e-commerce, e- related data mining, require ever greater capacity in order to handle the volume of data to be processed. In addition, with the advent of high bandwidth Internet and data-intensive applications such as high-definition TV (HDTV) and video and music on-demand, even smaller devices such as personal VCRs, PDAs, mobile phones, etc.,. Future increases in density are possible by taking advantage of shorter wavelength lasers, higher lens numerical aperture (NA), or by employing near-field techniques. Finally, optical data storage capacities have been increased by creating double-sided media. Another approach to increasing the effective storage capacity is quite unique for optical memory technologies. Fluorescent multilayer disc (FMD) used for large amount of data storage. This is three-dimensional storage. True three-dimensional optical storage opens up another dimension in which to increase the capacity of a given volume of media, with the objective of achieving a cubic storage element having the dimensions of the writing /reading laser wavelength. Even with current wavelengths of 650 µm, this should suffice to store up to a Terabytes of data.
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10-07-2010, 03:43 PM


.ppt   FMD.ppt (Size: 1.91 MB / Downloads: 207)

FLUORESCENT MULTILAYER DISC

Presented By:
B.Santosh
07895A0409

FLUORESCENT MULTILAYER DISC (FMD)

¢ Fluorescent Multi-Layer Discs (FMDs)
are a new technology being developed
by Constellation 3D Inc.
¢ FMD stores digital data in three
dimensions.
¢ It is an optical data storage format
similar in size and appearance to
regular CD-ROMs and DVDs.
¢ FMD is a readable disc.
¢ Max data transfer rates are
approximately 1GB/sec.
¢ FMD is a transparent disc.
¢ It consists of multiple data layers.
¢ Data is recorded on multiple layers
inside a disc.
¢ Capacity of each data layer is 4.7
GB.
¢ Recording, reading & storing of data
is accomplished by fluorescent
material.
¢ Fluorescent material emit radiation
when exited by an external light
source.
¢ FMD can hold up to 20-140GB of
data on 12-30 data layers, with total
thickness under 2mm.


OVERVIEW ON CD-ROM

¢ Single data layer
¢ Data layer - Reflective (Aluminum)
¢ Data bits stored in the form of
physically molded pits.
¢ Smooth area surrounding pits are
called lands.
¢ Red laser is used to read data.
¢ Storage capacity : 650MB.
¢ Data access speed range: 80 to 120ms
¢ Max data transfer rate: 5MB/sec.


OVERVIEW ON DVD-ROM

¢ DVD consists of 2 data layers.
¢ Data layer - Reflective (Aluminum)
¢ Distance between recording tracks: less than
half of CDs.
¢ Pit size is less than half of that of CD-ROMs.
¢ Red laser is used to read data.
¢ Require reduced laser wavelength to read small
size pits.
¢ Storage capacity : 4.7GB



TECHNOLOGICAL OVERVIEW OF FMD

¢ FMD is a transparent disc.
¢ No reflective layer like CD/DVD.
Technology in CD:
Ø Beam of laser hits on data layer
Ø It reflects from aluminum data
layer
Ø Fixed with a detector-receiver

Technology in FMD:

No reflected laser beam.
Principle of operation based on a
phenomenon Photochromism
An organic material called ËœStable
Photochromeâ„¢ is used as fluorescent
material.
Photochrome initially doesn't possess
fluorescent properties.
Photochrome when acted upon by
laser beam starts photo chemical
reactions & obtain the fluorescent
properties.
Simulation of fluorescent material
by laser to produce incoherent
light.
Emission of data stored incoherent
light.
Incoherent light passes through
adjacent data layers without
getting distorted.
Filtration of emitted light before it
reaches the drive's detector.
Filtration of emitted light before it
reaches the drive's detector.



FMD RECORDING

¢ Technology used: WORM (Write Once
Read Many)
¢ A series of rewritable discs called FMD
WORM
¢ Two rules to be followed while recording :
The write laser should able to
turn the fluorescence on or off.
Threshold power of laser for recording
& less power for reading.


Recording principles in FMD

Thermal:
Usage of materials that possesses fluorescent properties
from beginning (logical one).
When recording the segments, which are thermally acted
upon with laser, the fluorescent properties are lost (logical
zero)



Chemical:

Usage of a material that doesn't possess fluorescent
properties form the beginning.
When acting upon with a laser a photochemical reaction
starts, and the material gets fluorescent properties.
a low power laser is enough, or even a usual LED


FMD READ DEVICE

¢ Drives for FMD can easily understand
CD/DVD.
¢ FMD drives are similar to CD/DVD.
¢ The type of reading:
Successive reading
Successive-parallel reading
Parallel reading
Parallel Reading

A sequence of bits is recorded not
along a track but deep into layers.
Reading process is carried out with the help of a photosensitive
element (an array of CCD cameras)
Device can read low-power fluorescence of several tens MHz.
Reading speed reaches 1 gigabit/s
Mechanical speed of the drive is 450 times lower than that of DVD.



CONCLUSION

¢ Man™s need for additional storage space is increasing .
¢ The FMD Digital Cinema disc has the potential to provide a
secure, removable, single disc distribution method.
¢ The FMD can provide us with a staggering 140 GB of
storage space seems to be an enticing solution for the storage
- hungry masses.
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.ppt   RABIA.ppt (Size: 328.5 KB / Downloads: 96)
1. FLUORESCENT MULTILAYER DISC
It is a new data storage in optical format, similar in size and appearance to regular CD-ROMs and DVDs.
2. FLUORESCENT MULTILAYER CARD
Fluorescent Multi-layered Card provides high-capacity storage cards that are much cheaper than the current Compact Flash and MicroDrive card-type storage devices.
3. WHY FMD???
INCREASED DISC CAPACITY
QUICK PARALLEL ACCESS
MEDIA TOLERENCES
USAGE FLEXIBILITY
FMD ROM DISC AND DRIVE
FMD WROM DISC AND DRIVE
5. FMD/C TECHNOLOGY
DATA IS RECORDED ON MULTIPLE LAYERS
USE OF FLUORESCENT MATERIALS
6. DIGITAL DATA STORAGE
TECHNOLOGIES
VOLUMETRIC RECORDING
HOLOGRAPHIC STORAGE
MULTI LAYER STORAGE
FLUORESCENT MULTI LAYER
7. FMD/C ADVANTAGES
COMPATIBILITY
OPTICALLY TRANSPARENT
LOWER THAN CD/DVD SENSITIVITY TO IMPERFECTIONS IN MEDIA AND DRIVES
8. FMD-ROM OPERATING PRINCIPLE
PHOTOCHROMISM
9. INDUSTRIAL PRODUCTION PROTOTYPES
FMC CLEAR CARD ROM
FMD ROM
LAYER BONDING
EDGE SEALING
DISC DECORATION
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