Optical Computing

1. Optical Computing Joseph Clarkson

2. Advantages of Optical Computing • Massive parallelism • Spectral domain representations • Ultra fast • Volume holographic storage

3. Areas of Research • Optical learning architectures • Optical processing of advanced radar • Acousto-optic switch • Optical logic circuits • Dynamic organic hologram • Synthetic aperture radar processing

4. Optical Learning Architectures • Emulation of neural networks • Circuits with photodetectors and light modulators • Synapses are dynamic holographic interconnection gratings

6. 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

7. 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

8. 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

9. Optical Logic Circuits • Optical computers must have a fundamental logic gate • Based on interaction between optical solitons • Energy-efficient and ultra-fast NOR gate

10. Light Bullet Dragging

11. Dynamic Organic Hologram • Photorefractive crystals are expensive and limited in size • Reversible photochemical effects in dye molecules suspended in polymer hosts

12. Synthetic Aperture Radar Processing • Microwave hologram of the illuminated area • Real-time processing of imaging • Capable of automatic target recognition

13. Conclusions • High performance information processing systems • Fast parallel computation • Massive data storage • Energy efficient