3. INTRODUCTION
With the growth of computing technology the
need of high performance computers (HPC)
has significantly increased. Optics has been
used in computing for a number of years but
the main emphasis has been and continues to
be to link portions of computers, for
communications, or more intrinsically in
devices that have some optical application or
component (optical pattern recognition etc.)
3
4. WHY WE NEED OPTICAL
COMPUTERS?
• Rapid growth of the Internet
• Network speeds currently limited by
electronic circuits
• Terabit speeds are required
• Traditional silicon circuits have a physical
limit
4
5. WHAT IS THE OPTICAL
COMPUTING?
Consider E-mail
Electronic
To Photonic
Converter
.txt format
Fiber optic
cables
Optical Computers perform computations,
operate, store and transmit data using only
light. 5
8. SMART PIXEL
TECHNOLOGY
Smart pixel technology is a relatively new
approach to integrating electronic circuitry and
optoelectronic devices in a common framework.
The purpose is to leverage the advantages of
each individual technology and provide improved
performance for specific applications.
Here, the electronic circuitry provides complex
functionality and programmability while the
optoelectronic devices provide high-speed
switching and compatibility with existing optical
media.
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9. DEVICES FOR OPTICAL
COMPUTING
• Logic gates :
Logic gates are implemented optically by
controlling the population inversion that occurs
to produce lasing. A controlling laser is used to
control the population inversion thus causing
switching to occur.
• Holographic truth table:
Destructive interference with light to be emitted
or not is based on phase relationship.
• Logic based on gratings:
1 is represented vertical grating causing light
0 is represented by horizontal grating causing
darkness. 9
11. INTERCONNECTIONS IN OPTICAL
COMPUTING
• Fiber optic cables and optical transceivers are
widely used.
• Applications of optical communications like
fiber channel and computer networking are
already being used.
• Chip to Chip and On-Chip interconnection
possibilities are still being examined.
11
12. APPLICATION
• High speed communications
• Process satellite data.
• Storage area Network
• Optical crossbar interconnects are
used in a synchronous transfer modes
and shared memory multiprocessor
systems.
12
13. CONT….
• Optical Computing In VLSI Technology
Many researchers have been investigating suitable
optical logic devices, interconnection schemes, and
architectures. Furthermore, optics may provide
drastically new architectures to overcome some
architectural problems of conventional electrical
computers.
• Optical computing as expanders
The optical expander described utilizes high-speed
and high-space-bandwidth product connections that
are provided by optical beams in three dimensions.
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14. ADVANTAGES
• Small size
• High density
• High speed
• Low heating of junctions
• Dynamically reconfigurable and scalable
into larger or smaller topologies and
network
• Massively parallel computing capability
• Applications in artificial intelligence
applications
14
15. LIMITATION
• Although there is a basic speed limitation in
optoelectronic conversion delays ,WDM is used
to get around this limitation.
• Promising but there are problems regarding
dense organization of optical processing units
but DWDM techniques can be used to overcome
these limitations too.
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17. CONCLUSION
Research in optical computing has opened up
new possibilities in several fields related to high
performance computing, high-speed
communications. To design algorithms that
execute applications faster , software
development will have a major impact in the
future and the ground rules for the computing
may have to be rewritten.
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