26-02-2013, 11:17 AM
Optical Computing
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INTRODUCTION
Optical computing is a computing technology that performs its computation with photons
Optical computing is a technology that is in the research and theory stage. It is still in the early stages of development
The idea would be to make a computer that relies entirely on light (photons) instead of electricity (electrons) to do computing
An optical computer (also called a photonic computer) is a device that uses the PHOTONS in visible light or infrared ( IR ) beams, rather than electric current, to perform digital computations and transmit data.
An optical computer, besides being much faster than an electronic one, might also be smaller.
Bright flashes of laser light can be sent hundreds of miles along fine strands of specially made glass or plastic called OPTICAL FIBERS .
Electro-Optical Hybrid
Use optical fibers and electric parts to read and direct data from the processor
Light pulses send information instead of voltage packets.
Processors change from binary code to light pulses using lasers.
Information is then detected and decoded electronically back into binary.
Smart pixel technology
Smart pixel technology is a relatively new approach to integrating electronic circuitry and optoelectronic devices in a common framework.
Here, the electronic circuitry provides complex functionality and programmability.
While the optoelectronic devices provide high-speed switching and compatibility with existing optical media.
Arrays of these smart pixels leverage the parallelism of optics for interconnections as well as computation. A smart pixel device, a light emitting diode under the control of a field effect transistor can now be made entirely out of organic materials on the same substrate for the first time. In general, the benefit of organic over conventional semiconductor electronics is that they should lead to cheaper, lighter, circuitry that can be printed rather than etched.
Wavelength division multiplexing
Wavelength division multiplexing is a method of sending many different wavelengths down the same optical fiber. Using this technology, modern networks in which individual lasers can transmit at 10 gigabits per second through the same fiber at the same time.
WDM can transmit up to 32 wavelengths through a single fiber, but cannot meet the bandwidth requirements of the present day communication systems. So nowadays DWDM (Dense wavelength division multiplexing) is used. This can transmit up to 1000 wavelengths through a single fiber. That is by using this we can improve the bandwidth efficiency.
Drawbacks of Optical Computing
Today’s 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.
Optical components and their production is still expensive
New expensive high-tech factories have to be built
Future Trends
The Ministry of Information Technology has initiated a photonic development program. Under this program some funded projects are continuing in fiber optic high-speed network systems. Research is going on for developing new laser diodes, photo detectors, and nonlinear material studies for faster switches.
By applying some of the advantages of visible and/or IR networks at the device and component scale, a computer might someday be developed that can perform operations 10 or more times faster than a conventional electronic computer.