Title: OPTICAL COMPUTERS
1OPTICAL COMPUTERS
- By, Under The
Guidance of - Nirmal RaJ
Asst . Prof. Nelanjana Bowmick - Abhishek B Mane
2What is Optical Computer
- An optical computer is a computer that uses
photons in visible light or IR beams to perform
digital computation .
3EXAMPLES
.txt format
Fiber optic cables
Electronic To Photonic Converter
Optical Computers perform computations, operate,
store and transmit data using only light.
5
4Why Optical Computers...?
- In silicon computers, the speed of computers was
achieved by miniaturizing electronic components. - It is also estimated that the number of
transistor switches that can be put onto a chip
doubles every 18 months. - So further miniaturization of size introduces
several problems such as dielectric breakdown,
hot carriers, and short channel effects etc.
5Advantages...
- Increase in the speed of computation.
- Immune to electromagnetic interference.
- Free from electrical short circuits.
- Have low-loss transmission and large bandwidth.
- Speed of light in photonic circuits will be close
to speed of light in vacuum - Capable of communicating several channels in
parallel without interference. - Possesses superior storage density and
accessibility - No power loss due to excess of heating.
- Life of the hardware of optical computer is more.
6Parallel communication
7Optical computation ?
- Light in the place of Electron
- Uses optical components
- Transistors, logical gates etc. are simulated
using optics. - All-optical components require a high level of
laser power to function as required. - Send pulses of light instead of pulses of
electricity -
8Optical Components...
- VCSEL-vertical cavity surface emitting micro
laser - VCSELs have high performance and low cost
advantages - Emits light in a cylindrical beam vertically from
the surface of a fabricated wafer - Low-cost potential because the devices are
completed and tested at the wafer level
9Optical interconnection of circuit using VCSEL
and photodiodes
- VCSEL converts the electrical signal to optical
using lens and micromirrors
10- Photonic Crystals- crystals designed to replace
transistors in optical computers. - Optical nanostructures that are designed to
affect the motion of Photons.
11- SLMs - Spatial light modulators , play an
important role in optical processing, for
inputting information on light beams, and
displays. - A set of memory cells laid out on a regular grid
and value in each cell contribute to manipulate
the behaviour of optical activity.
12Logical Gates Logic gates are the
building blocks of any digital system. An optical
logic gate is a switch that controls one light
beam with another. It is "on" when the device
transmits light, and "off" when it blocks the
light.
13- Smart pixels -Smart pixels, the union of optics
and electronics - Expands the capabilities of electronic systems
and enables optical systems with high levels of
electronic signal processing. - Some examples
- LED- Light emitting diode with FET- Field
effect transistor.
14Use of Optics in computing..
- Use of optics in intercommunication
- Here optical fibres are used communicate
internally like communicating with peripherals
etc. - the use of free-space optical interconnects as a
potential solution to alleviate bottlenecks
experienced in electronic. - Optical sorting and optical crossbar
inter-connects are used in asynchronous transfer
modes.
15Few Examples
16- Use of optics in Memory storage-
- Mass storage, which is implemented by optical
disks or by holographic storage systems. - The primary benefits offered by holographic
optical data storage over current storage
technologies include significantly higher storage
capacities and faster read-out rates. - A holographic memory can store data in the form
of a hologram within a crystal. - The analog nature of these devices means that
data can be stored at much higher density than
data written by conventional devices.
17Process of Memory Storage using Optical Computing
18Current work and Improvements.
- By NASA
- The thin films being developed.
- Can perform switching, signal processing and
frequency doubling - NASA have developed and built all-optical logic
gate circuits for data processing
THIN FILM TRANSISTOR
19- By IBM
- IBM announced that its researchers have built a
device capable of delaying the flow of light on a
silicon chip, a requirement to one day allow
computers to utilize optical communications to
achieve better performance. - Almaden Research Center at IBM have developed
ultrafast data storage devices that use laser
pulses
20- At the University of Bristol in the UK
- Researchers have made a prototype optical quantum
computer chip and used it to perform a
mathematical calculation for the first time. - Intel claims optical computing "milestone
- Intel's hybrid silicon laser research has allowed
it to transfer 50Gb/s down a single fibre-optic
channel.Intel has made a breakthrough in optical
connection technology with the world's first
end-to-end silicon photonics connection, which
the company claims "could revolutionise computer
design, dramatically increase performance, and
save energy."
21Challenges...
- Finding materials that can be mass produced
- Practical limits of eight to eleven bits of
accuracy-intensity fluctuations. - Computation is a nonlinear process in which
multiple signals must interact to compute the
answer. - Making photonic crystals is a difficult process.
- Putting optical switches on computer chips.
- Fabrication.
22The Smallest Laser Ever Made
- Surface-plasmon lasers could enable a new
generation of computers based on nanophotonics
23- DRAWBACKS
- Todays materials require much high power to work
in consumer products, coming up with the right
materials may take five years or more. - Optical computing using a coherent source is
simple to compute and understand, but it has many
drawbacks like any imperfections or dust on the
optical components will create unwanted
interference pattern due to scattering effects.
Incoherent processing on the other hand cannot
store phase information.
24CONCLUSION
- Optical technology promises massive upgrades in
the efficiency and speed of computers, as well as
significant shrinkage in their size and cost. - Even though pure Optical computer has many
challenges hybrid opto-electrical computer can be
expected very soon, and in near future pure
optical computer too..
25 Thank You
26QUESTIONS