FLUORESCENT MULTILAYER DISC A SEMINAR REPORT BY K.VISHNU VARDHAN REDDY (07N71A0580)DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING DRK INSTITUTE OF SCIENCE AND TECHNOLOGY (Affiliated to JNTU, Hyderabad) Bowrampet (V), via Air Force Academy Hyderabad-500043
ABSTRACT FMD (Fluorescent Multilayer Disk), which can provide usCompact discs were a with a staggering 140 GB ofrevolutionary product at its storage space, seems to be antime and influenced many enticing solution for thespheres of human activity. storage-hungry masses.People started recording music Constellation 3Ds technologyof high quality, which didnt implements the concept of theget worse with the time as it volumetric storage ofhappens to be on tape. As soon information. Data is recordedas CDs appeared in computer on multiple layers locatedindustry they immediately inside a disc or a card, asbecame an undoubted helper opposed to the single layerboth for users and for method available in compactprogrammers. The latter were discs, and double layer methodable to increase volume of their available in DVD’s. Theprogram products by adding recording, reading and storingvideo and audio elements of the information isetc.FMD , which can provide accomplished through the useus with a staggering 140 GB of of fluorescent materialsstorage space, seems to be an embedded in pits and groovesenticing solution for the in each of the layers. Thestorage-hungry masses.The fluorescent material emitscompany Constellation 3D radiation when excited by andemonstrates a new format:
external light source. The fluorescent material in eachinformation is then decoded as layer which reflects a differentmodulations of the intensity frequency of light than theand color of the emitted other layers, making it possibleradiation. to shine the light through the disc and read the properINTRODUCTION frequency for the expected layer. Because of this, the mainFluorescent Multilayer Disc, limitation on the number ofabbreviated as FMD, is a data layers, besides how manystorage medium that follows different materials can bethe idea previously used in found to be used, would be toDVDs, making multiple layers keep the disc from being tooto get more data on one disc, thick.but takes the idea to a new A 50 GB prototype disc waslevel. Because the normal demonstrated at the Comdexreflective layers were too industry show in Novemberlimiting, making it nearly 2000. First generation FMDsimpossible to get more than were to have roughly 100 GBtwo layers on a disc, per disc.Constellation 3D decided to After the shutting down offind a new way to reflect the Constellation 3D due to alight that would not interfere scandal and the companywith other layers. To do this, consequently running out ofthey have a different
money, a new company called FMD, which can provide usD Data Inc. was formed which with a staggering 140 GB ofacquired the entire patent storage space, seems to be anportfolio of Constellation 3D in enticing solution for the2003. The company is storage-hungry masses. Thedetermined to bring multilayer company Constellation 3Doptical disc technology to the demonstrates a new format:market . FMD (Fluorescent Multilayer Disk), which can provide us Compact discs with a staggering 140 GB ofwere a revolutionary product at storage space, seems to be anits time and influenced many enticing solution for thespheres of human activity. storage-hungry masses.People started recording musicof high quality, which didnt Constellation 3Dsget worse with the time as it technology implements thehappens to be on tape. As soon concept of the volumetricas CDs appeared in computer storage of information. Data isindustry they immediately recorded on multiple layersbecame an undoubted helper located inside a disc or a card,both for users and for as opposed to the single layerprogrammers. The latter were method available in compactable to increase volume of their discs, and double layer methodprogram products by adding available in DVD’s. Thevideo and audio elements etc. recording, reading and storing
of the information is 405 nm blue lasers, givingaccomplished through the use capacities of up to a terabyte.of fluorescent materials OPERATING PRINCIPLESembedded in pits and groovesin each of the layers. Thefluorescent material emits The pits in an FMD are filledradiation when excited by an with fluorescent material.external light source. The When coherent light from theinformation is then decoded as laser strikes a pit the materialmodulations of the intensity glows, giving off incoherentand color of the emitted light of a different wavelength.radiation. Since FMDs are clear, this light is able to travel through many layers unimpeded. The clearDEVELOPMENT discs, combined with the ability to filter out laser light (based onA 50 GB prototype disc was wavelength and coherence),demonstrated at the COMDEX yield a much greater signal-to-industry show in November noise ratio than reflective2000. First generation FMDs media. This is what allowswere to use 650 nm red lasers, FMDs to have many layers. Theyielding roughly 140 GB per main limitation on the numberdisc. Second and third of layers in an FMD is thegeneration FMDs were to use overall thickness of the disc.
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 onlyFLUORESCENT the information-bearingMULTILAYER fluorescent light is detected, thus reducing the effect of stray The concept of multi- light and interference.layer, fluorescent cards/discs Theoretical studies, confirmed(FMD/C) is a unique by experimental results, havebreakthrough, solving the shown that in conventionalproblems of signal degradation. reflection systems the signalHere, the storage layer is coated quality degrades rapidly withwith a fluorescent material. the number of layers. InWhen the laser beam hits the fluorescent read out systems,layer, fluorescent light is on the other hand, the signalemitted. This emitted light has quality degrades much morea different wavelength from the slowly with each additional
layer .Research has shown that also been demonstrated usingmedia containing up to a propeirtary photochromichundred layers are currently compound.feasible, thereby increasing thepotential capacity of a single TECHNOLOGICALcard or disk to hundreds of PROCESSGigabytes. Use of blue laserswould increase the capacities to Technological process of FMover 1 Terabyte. discs is divided into two types: In the first one there used a method of hotFLUORESCENT stamping. Each layer is reachedMATERIAL by pressing of polycorboneThe fluorescent material . layer with two stamps (Master-arguably, the .main ingredient. copies) at high temperature. Soof FMD technology converts we receive one layer with twoincident (incoherent) laser light informational sides. Then, pitsinto incoherent fluorescent starts being fill with fluorescentlight. C3D has several material material. And when it becomesformulations. The most- hard the informational layersdeveloped material is used in are pressed.readonly discs. Writable In the picture you can see a(recordable) and re-writable structure of a 7-layer discformulations (and their produced according to thecorresponding drives) have described method.
While rotating, photopolymer matter is evenly brought in in the space between stamp surface and plastic film. Later, when the photopolymer matter becomes hard the film getThe second method uses a detached from the stampprocess of photopolymerization surface. The base plate nowwhen a multiple disc is reached contains pits of definiteby stacking of discs one after geometry. A pits geometry isanother which are made from better in terms of quality thanthin informational layers. that received whenManufacture of one manufacturing matrices for CDinformational layer lies in or DVD since thosemanufacture of plastic film technologies use a process ofwith definite optical stamping of pits. When a layercharacteristics. The film is 25 to with the required position of30 micron in width. The film pits is ready, they are filledwhich will get information with fluorescent material (itsoon is either stamped or cut covers evenly the wholeout with a laser. After that the informational side). After thatfilm is installed on an external the surface is processedsurface of a nickel matrix that chemically in order to reachcarries a negative copy of necessary contrast of pits andproduced informational layer. flats. Then, in order to check
the copy for different defects, and bonded together underphotoelements get excited and pressure. The result is a storagethe whole picture is analyzed media having multiple layers: awith the help of CCD cameras. Fluorescent Multilayer Disc.After that the layers are "stuck" Photo-Polymerization (2P)to the base plate 0.6 mm in Process:width. And all this is coveredwith a protective layer which This method, incan be used for graphics which layers are sequentiallydecoration. In order to prevent replicated by creating .thina physical contact with replicas., will eventually allowinformational layers on the FMD to incorporate up to 100edge of the disc this area is layers .filled as well with polymericmaterial, like in CD or DVDtechnologies.Hot-Embossing: Using hotmetal stampers, thinpolycarbonate sheets areembossed on both sides. Afterthe sheets cool, the embossedpits are filled with fluorescentdye. After the dye is cured, theindividual sheets are stacked
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 isADVANTAGES twice that for coherent light based systems .1. The multi-layer system is 7. FMD technology isoptically transparent and compatible with current CDhomogeneous. and DVD formats, having the2. Low absorption in each layer. capacity to handle the same3. No absorption for the data rates over each of its layersemitted signal fluorescent light. 8.Prevents problem of4. Lower than CD/DVD interference since it uses ansensitivity to imperfections in incoherent fluorescent light.media and drives. Thefluorescent technique does SECURITYnot depend on interference
limited amount of time (Cohen,FMD will offer an 2001). One can easily see thatextraordinary amount of FMD.ssecurity. In addition to security options will be usefulcomplying with the newest beyond cinema. Governments,and most sophisticated businesses large and small,encryption technologies, FMD.s and consumers will all benefitunique dye chemistry will offer from themmuch greater control overaccess to intellectual property.In the digital cinema realm, forexample, FMD.s capacity ofeach frame (there are 24 framesallows for digital watermarkingper second). Dyes can even be DIFFERENCES BETWEENcustomized to work exclusively CD/DVD/FMDwith FMD players used incinemas, rendering stolen DVcopies inaccessible to those Parameter CD FMD Dusing consumer drives. As forprotection from mass- Discduplicating pirates, dyes can be diameter, 120 120 130designed to last only for a mmspecific numberof plays or Capacity, 0,6 17,4 50,8
GBytes 4 2 (on CONCLUSIONNumber of 1 each 12 The rapidlayers side technological development that ) is taking place in storageDistance devices has also made the manbetween think about the needs and the - 40 25±5layers , requirements for the storagemicron devices. Man’s need for additional storage space isTotal width increasing The FMD Digitalof 0,1 Cinema disc has the potentialinformation 2 275 1 to provide a secure ,al layers, removable, single discmicron distribution method. The FMD DV Modifie can provide us with aFormat CD D d DVD staggering 140 GB of storageDistance space seems to be an enticingbetween solution for the storage- hungry 1,6 0,74 0,8tracks, masses.micron