Opticalcomputing FINAL 2

7/29/2019 Opticalcomputing FINAL 2

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Submitted to: Submitted by: MR. MANISH RAVERKAR MORBIYA SACHIN C

HOD ELECTRONICS & COMMUNICATION

(10EAYEC202)

Optical Computing Technology


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Introduction Why we use optics for computing

Optical computer

Optical fiber cable

Optical components for computingVCSEL

SMART PIXEL TECHNOLOGY

WDM

Merits Drawback

Conclusion

CONTENTS


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Introduction

Optical computing was a hot research area in 1980s. But thework tapered off due to materials limitations.

Using light, instead of electric power, for performing

computations.

This choice is motivated by several features that light has:

It is very fast.

It can be easily manipulated (divided, transported,

delayed, split, etc)

It is very well suited for parallelization.


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More Optical computing technology is, in general, developing in two

directions.

One approach is to build computers that have the samearchitecture as present day computers but using optics that is

Electro optical hybrids.

Another approach is to generate a completely new kind ofcomputer, which can perform all functional operations in

optical mode.


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Why we Use Optics forComputing?

One of the theoretical limits on how fast a computer can functionis given by Einsteins principle that signal cannot propagatefaster than speed oflight.

To make computers faster, their components must be smaller andthere by decrease the distance between them.

Optical computing can solve miniaturization problem.

Optical data processing can be performed in parallel.

In optical computing, the electrons are replaced by photons


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Silicon Machines Vs Optical Computers


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OPTICAL COMPUTER An optical computer (also called a photonic computer) is a devicethat uses the PHOTONS in visible light or infrared beams, rather

than electric current to perform digital computations.

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 finestrands of specially made glass or plastic called OPTICAL FIBERS.

Instead of transistors, such a computer will haveTRANSPHASORS


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More

And unlike transistors, transphasors can be built to handleseveral incoming signals at once.

Beams of light can crisscross and overlap without becoming

mixed up, whereas crossed electric currents would gethopelessly confused.

The arrangement of connections and switches would not haveto be flat, as in an electronic computer. It could be placed in

any direction in space, allowing totally new designs ininformation processing.


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Optic Fiber cables made of glass or

plastic

Glass opticfiber

Plastic opticfiber


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OPTICAL COMPONENTS FORCOMPUTING

VCSEL

SMART PIXEL TECHNOLOGY WDM

SLM


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1. VCSEL (VERTICAL CAVITY SURFACEEMITTING LASER)

VCSEL(pronouncedvixel)is a semiconductor vertical cavitysurface emitting laser diode that emits light in a cylindrical

beam vertically from the surface of a fabricated wafer.

But rather than reflective ends, in a VCSEL there are severallayers of partially reflective mirrors above and below the

active layer.

Layers of semiconductors with differing compositions createthese mirrors, and each mirror reflects a narrow range of

wavelengths back in to the cavity in order to cause light

emission at just one wavelength.


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Vertical Cavity Surface Emitting Laser

850nm VCSEL


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2. SMART PIXEL TECHNOLOGY

Smart pixel technology is a relatively new approach to integratingelectronic circuitry and optoelectronic devices in a commonframework.

Here, the electronic circuitry provides complex functionality and

programmability.

While the optoelectronic devices provide high-speed switchingand compatibility with existing optical media.

Arrays of these smart pixels leverage the parallelism of optics forinterconnections as well as computation..


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3. WDM (WAVELENGTH DIVISIONMULTIPLEXING)

Wavelength division multiplexing is a method of sending many

different wavelengths down the same optical fiber.

WDM can transmit up to 32 wavelengths through a single fiber,but cannot meet the bandwidth requirements of the present day

communication systems.

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.


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MERITS

Optical computing is at least 1000 to 100000 times faster than

todays silicon machines. Optical storage will provide an extremely optimized way to store

data, with space requirements far lesser than todays silicon chips.

No short circuits, light beam can cross each other without

interfering with each others data. Higher performance

Higher parallelism

Less heat is released

Less noise

Less loss in communication


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Drawback Todays materials require much high power to work in

consumer products, coming up with the right materialsmay take five years or more.

Optical computing using a coherent source is simple to

compute and understand, but it has many drawbacks likeany 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


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CONCLUSIONResearch 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 ,the specific properties of optics must be considered, such as

their ability to exploit massive parallelism, and global

interconnections. As optoelectronic and smart pixel devices mature,

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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THANK YOU

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Opticalcomputing FINAL 2