SUBMITTED TO: SUBMITTED BY: JAIL SINGH (H.O.D. E.C.E. Deptt.) Roll No. 5309219

E.C.E. B. Tech.,8 th Sem.

 HINDUSTAN INSTITUTE OF TECHNOLOGY & MANAGEMENT DHEEN (AMBALA) KURUKSHETRA UNIVERSITY, KURUKSHETRA

FLUROSCENT MULTILAYER

DISC

FLUORESCENT MULTILAYER DISC

What is FMD?Fluorescent Multilayer disc is an optical disc

that uses fluorescent rather than reflective material to store data.

It is an three dimensional storage disc.

Why FMD?

Increased disc Capacity. Quick parallel access and retrieval

information. Media tolerances. Usage Flexibility.

Operating Principle:

The principle operation of FMD is based on a

phenomenon of photochromism. The laser beam when focused on the

informationmaterial the material starts radiating than

reflecting. The laser beam causes the photochrome

material to posses the fluorescent properties . The fluorescence is caught up by a device

calledphoto receiver.

The usage of photochrome material with increasing

the number of information layers do not make the signal

worse which is not in case of other optical discs.

The developers state that with blue laser(480nm) it is possible to increase density up to Terabytes on the disc.

This technology prevents the problem of interference

since we are using photochrome material which posses the fluorescent properties.

Model of FMD:

Comparison of Disc Layers:

FMD READ DEVICES Parallel Reading- this

technology allows parallel reading; it means that a sequence of bits is recorded not along a track but deep into layers. That's why we receive three types of data reading: successive, successive-parallel and parallel.

And the reading speed reaches 1 Gigabit/s. We should notice that mechanical speed of the drive is 450 times lower than that of DVD.

TECHNOLOGY OVERVIEW

In case of fluorescent discs the quality of the signal gets affected much slower with increasing number of layers.

According to FMD-ROM developers, even with a hundred layers a useful signal will be acceptable.

They also state that with a blue laser (480 nm) it is possible to increase record density up to tens of Terabyte on one FM disc.

Also features parallel reading.

Technological Process:

Hot Stamping: The layer is pressed with polycarbonate

and stamped twice with hot temperature. This results in two information layer with pits on each side and

filledwith fluorescent material.

Photoploymerisation:This process is carried out in order to prevent a physical contact with information layer on the edge of the disc this is filled with

polymeric material.

Advantages of FMD:

Prevents problem of interference since it uses an

incoherent fluorescent light. Compatible with CD and DVD formats

with more storage area and faster access. Fluorescent technology do not require

special manufacturing conditions.

Applications:

Data warehouses. HDTV. Mobile phones . PVR(Digital Cinema Film) Ability to store the whole of a series

of TV programme (e.g. 20 episodes)

CD vs DVD vs FMD:

PARAMETERPARAMETERSS

CDCD DVDDVD FMDFMD

1. Disc 1. Disc diameter diameter

120mm120mm 120mm120mm 120mm120mm

2. Capacity 2. Capacity 750MB750MB 4GB 4GB 50GB+50GB+

3. Wavelength3. Wavelength 780nm780nm 650nm650nm 480-480-530nm530nm

4. Distance 4. Distance b/w tracksb/w tracks

1.6micro1.6micronn

0.85micro0.85micronn

0.80mic0.80micronron

5.No.of layers5.No.of layers 11 22 1212

15

Thank You