FMD (Fluorescent Multilayer Disk) is a data storage medium that can store up to 140 GB of data using multiple fluorescent layers, overcoming limitations of CDs and DVDs. Constellation 3D developed this technology, demonstrating a 50 GB prototype. Data is recorded in pits filled with fluorescent materials that emit unique wavelengths when read by a laser. This allows individual layers to be read without interference. FMD promises greatly increased storage capacity over existing optical discs.

1. 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

2. ABSTRACT FMD (Fluorescent Multilayer
Disk), which can provide us
Compact discs were a with a staggering 140 GB of
revolutionary product at its storage space, seems to be an
time and influenced many enticing solution for the
spheres of human activity. storage-hungry masses.
People started recording music
Constellation 3D's technology
of high quality, which didn't
implements the concept of the
get worse with the time as it
volumetric storage of
happens to be on tape. As soon
information. Data is recorded
as CDs appeared in computer
on multiple layers located
industry they immediately
inside a disc or a card, as
became an undoubted helper
opposed to the single layer
both for users and for
method available in compact
programmers. The latter were
discs, and double layer method
able to increase volume of their
available in DVD’s. The
program products by adding
recording, reading and storing
video and audio elements
of the information is
etc.FMD , which can provide
accomplished through the use
us with a staggering 140 GB of
of fluorescent materials
storage space, seems to be an
embedded in pits and grooves
enticing solution for the
in each of the layers. The
storage-hungry masses.The
fluorescent material emits
company Constellation 3D
radiation when excited by an
demonstrates a new format:

3. external light source. The fluorescent material in each
information is then decoded as layer which reflects a different
modulations of the intensity frequency of light than the
and color of the emitted other layers, making it possible
radiation. to shine the light through the
disc and read the proper
INTRODUCTION
frequency for the expected
layer. Because of this, the main
Fluorescent Multilayer Disc, limitation on the number of
abbreviated as FMD, is a data layers, besides how many
storage medium that follows different materials can be
the idea previously used in found to be used, would be to
DVDs, making multiple layers keep the disc from being too
to get more data on one disc, thick.
but takes the idea to a new A 50 GB prototype disc was
level. Because the normal demonstrated at the Comdex
reflective layers were too industry show in November
limiting, making it nearly 2000. First generation FMDs
impossible to get more than were to have roughly 100 GB
two layers on a disc, per disc.
Constellation 3D decided to After the shutting down of
find a new way to reflect the Constellation 3D due to a
light that would not interfere scandal and the company
with other layers. To do this, consequently running out of
they have a different

4. money, a new company called FMD, which can provide us
D Data Inc. was formed which with a staggering 140 GB of
acquired the entire patent storage space, seems to be an
portfolio of Constellation 3D in enticing solution for the
2003. The company is storage-hungry masses. The
determined to bring multilayer company Constellation 3D
optical disc technology to the demonstrates a new format:
market . FMD (Fluorescent Multilayer
Disk), which can provide us
Compact discs
with a staggering 140 GB of
were a revolutionary product at
storage space, seems to be an
its time and influenced many
enticing solution for the
spheres of human activity.
storage-hungry masses.
People started recording music
of high quality, which didn't Constellation 3D's
get worse with the time as it technology implements the
happens to be on tape. As soon concept of the volumetric
as CDs appeared in computer storage of information. Data is
industry they immediately recorded on multiple layers
became an undoubted helper located inside a disc or a card,
both for users and for as opposed to the single layer
programmers. The latter were method available in compact
able to increase volume of their discs, and double layer method
program products by adding available in DVD’s. The
video and audio elements etc. recording, reading and storing

5. of the information is 405 nm blue lasers, giving
accomplished through the use capacities of up to a terabyte.
of fluorescent materials OPERATING PRINCIPLES
embedded in pits and grooves
in each of the layers. The
fluorescent material emits
The pits in an FMD are filled
radiation when excited by an
with fluorescent material.
external light source. The
When coherent light from the
information is then decoded as
laser strikes a pit the material
modulations of the intensity
glows, giving off incoherent
and 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 clear
DEVELOPMENT
discs, combined with the ability
to filter out laser light (based on
A 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 reflective
2000. First generation FMDs
media. This is what allows
were to use 650 nm red lasers,
FMDs to have many layers. The
yielding roughly 140 GB per
main limitation on the number
disc. Second and third
of layers in an FMD is the
generation FMDs were to use
overall thickness of the disc.

6. 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
FLUORESCENT the information-bearing
MULTILAYER 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, have
breakthrough, solving the shown that in conventional
problems of signal degradation. reflection systems the signal
Here, the storage layer is coated quality degrades rapidly with
with a fluorescent material. the number of layers. In
When the laser beam hits the fluorescent read out systems,
layer, fluorescent light is on the other hand, the signal
emitted. This emitted light has quality degrades much more
a different wavelength from the slowly with each additional

7. layer .Research has shown that also been demonstrated using
media containing up to a propeirtary photochromic
hundred layers are currently compound.
feasible, thereby increasing the
potential capacity of a single
TECHNOLOGICAL
card or disk to hundreds of
PROCESS
Gigabytes. Use of blue lasers
would increase the capacities to Technological process of FM
over 1 Terabyte. discs is divided into two types:
In the first
one there used a method of hot
FLUORESCENT
stamping. Each layer is reached
MATERIAL
by pressing of polycorbone
The fluorescent material . layer with two stamps (Master-
arguably, the .main ingredient. copies) at high temperature. So
of FMD technology converts we receive one layer with two
incident (incoherent) laser light informational sides. Then, pits
into incoherent fluorescent starts being fill with fluorescent
light. C3D has several material material. And when it becomes
formulations. The most- hard the informational layers
developed 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 disc
formulations (and their
produced according to the
corresponding drives) have
described method.

8. 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 get
The second method uses a
detached from the stamp
process of photopolymerization
surface. The base plate now
when a multiple disc is reached
contains pits of definite
by stacking of discs one after
geometry. A pit's geometry is
another which are made from
better in terms of quality than
thin informational layers.
that received when
Manufacture of one manufacturing matrices for CD
informational layer lies in or DVD since those
manufacture of plastic film technologies use a process of
with definite optical stamping of pits. When a layer
characteristics. The film is 25 to with the required position of
30 micron in width. The film pits is ready, they are filled
which will get information with fluorescent material (it
soon is either stamped or cut covers evenly the whole
out with a laser. After that the informational side). After that
film is installed on an external the surface is processed
surface of a nickel matrix that chemically in order to reach
carries a negative copy of necessary contrast of pits and
produced informational layer. flats. Then, in order to check

9. the copy for different defects, and bonded together under
photoelements get excited and pressure. The result is a storage
the whole picture is analyzed media having multiple layers: a
with 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 covered
with a protective layer which
This method, in
can be used for graphics
which layers are sequentially
decoration. In order to prevent
replicated by creating .thin
a physical contact with
replicas., will eventually allow
informational layers on the
FMD to incorporate up to 100
edge of the disc this area is
layers .
filled as well with polymeric
material, like in CD or DVD
technologies.
Hot-Embossing: Using hot
metal stampers, thin
polycarbonate sheets are
embossed on both sides. After
the sheets cool, the embossed
pits are filled with fluorescent
dye. After the dye is cured, the
individual sheets are stacked

10. 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
ADVANTAGES
twice that for coherent light
based systems .
1. The multi-layer system is
7. FMD technology is
optically transparent and
compatible with current CD
homogeneous.
and DVD formats, having the
2. Low absorption in each layer. capacity to handle the same
3. No absorption for the data rates over each of its layers
emitted signal fluorescent light. 8.Prevents problem of
4. Lower than CD/DVD interference since it uses an
sensitivity to imperfections in incoherent fluorescent light.
media and drives. The
fluorescent technique does
SECURITY
not depend on interference

11. limited amount of time (Cohen,
FMD will offer an 2001). One can easily see that
extraordinary amount of FMD.s
security. In addition to security options will be useful
complying with the newest beyond cinema. Governments,
and most sophisticated businesses large and small,
encryption technologies, FMD.s and consumers will all benefit
unique dye chemistry will offer from them
much greater control over
access to intellectual property.
In the digital cinema realm, for
example, FMD.s capacity of
each frame (there are 24 frames
allows for digital watermarking
per second). Dyes can even be DIFFERENCES BETWEEN
customized to work exclusively CD/DVD/FMD
with FMD players used in
cinemas, rendering stolen
DV
copies inaccessible to those Parameter CD FMD
D
using consumer drives. As for
protection from mass- Disc
duplicating pirates, dyes can be diameter, 120 120 130
designed to last only for a mm
specific numberof plays or Capacity, 0,6 17,4 50,8

12. GBytes 4
2
(on CONCLUSION
Number of
1 each 12 The rapid
layers
side technological development that
) is taking place in storage
Distance devices has also made the man
between think about the needs and the
- 40 25±5
layers , requirements for the storage
micron devices. Man’s need for
additional storage space is
Total width
increasing The FMD Digital
of
0,1 Cinema disc has the potential
information 2 275
1 to provide a secure ,
al layers,
removable, single disc
micron
distribution method. The FMD
DV Modifie can provide us with a
Format CD
D d DVD
staggering 140 GB of storage
Distance space seems to be an enticing
between solution for the storage- hungry
1,6 0,74 0,8
tracks, masses.
micron

13. REFERENCES
1.www.en.wikipedia.org/
wiki.
2.www.ixbtlabs.com/articles
3.www.seminartopic.org.
4. http://news.bbc.co.uk/h
i/english/entertainment
/newsid_1190000/11907
24.stm.
5. http://www.fmdinsider.
com. February 1, 2002.
6. Sandler, Ingolf. (1999).
White Paper .
Fluorescent Multilayer
optical storage.
www.fabtech.org/datate
ch/journals/edition6/do
wnloads/dt6_15_22.pdf.