Optical Computing
Joseph Clarkson
Advantages of Optical
Computing
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Massive parallelism
Spectral domain representations
Ultra fast
Volume holographic storage
Areas of Research

Optical learning architectures
 Optical processing of advanced radar
 Acousto-optic switch
 Optical logic circuits
 Dynamic organic hologram
 Synthetic aperture radar processing
Optical Learning Architectures

Emulation of neural networks
 Circuits with photodetectors and light
modulators
 Synapses are dynamic holographic
interconnection gratings
Optical Learning Architectures
- Results

Back propagation and competitive learning
successfully implemented
 First self-aligning holographic multi-layer
neural networks
 First winner-take-all VLSI/liquid crystal
modulator array
Optical Processing of
Advanced Radar

Processing wide-bandwidth data from large
phased array radars
 Nearly intractable for conventional digital
signal processors
 Use dynamic volume holograms
 Implemented an adaptive phased-array
radar optical processor with photorefractive
crystals
Acousto-optic Switch

Mechanical switches are too slow for
routing signals in optical fibers
 Light is diffracted from each fiber to desired
destination fiber
 Low loss
Optical Logic Circuits

Optical computers must have a fundamental
logic gate
 Based on interaction between optical
solitons
 Energy-efficient and ultra-fast NOR gate
Light Bullet Dragging
Dynamic Organic Hologram

Photorefractive crystals are expensive and
limited in size
 Reversible photochemical effects in dye
molecules suspended in polymer hosts
Synthetic Aperture Radar
Processing

Microwave hologram of the illuminated
area
 Real-time processing of imaging
 Capable of automatic target recognition
Conclusions

High performance information processing
systems
 Fast parallel computation
 Massive data storage
 Energy efficient