Optoelectronic devices for information storage and processing

Citation

Drolet, Jean-Jacques P. (1997) Optoelectronic devices for information storage and processing. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/80x4-rf73. https://resolver.caltech.edu/CaltechETD:etd-01102008-090916

Abstract

Optoelectronic information storage and processing systems offer many important advantages compared to their electronic and magnetic counterparts: speed, massive parallelism and insensitivity to interference. Optoelectronic devices are a pivotal technology in the implementation of such systems. Devices consisting of optical inputs and outputs and information processing circuits are needed to interface optoelectronic components and modules to electronic systems, and to perform operations that are more difficult to reliably implement using optics alone. The main thrust of our research is to develop and evaluate optoelectronic technologies conducive to highly integrated optoelectronic components and systems for cost-effective information storage and processing.

At the device level, we describe a simple and inexpensive method for fabricating liquid crystal modulators on silicon integrated circuits. The modulators provide analog amplitude or phase modulation at low voltages. They are compatible with mainstream very-large-scale-integration processes and require only a minimal amount of post-processing performed on conventionally fabricated die. Experimental data are presented and compared to theoretical predictions.

At the chip level, we present an innovative optoelectronic integrated circuit functioning as an optically or electrically addressed spatial light modulator. The device merges the functions of a spatial light modulator and a detector array in a holographic memory system. Moreover, it helps refresh dynamic holograms which slowly decay in a read/write photorefractive memory as a result of their exposure to the reference beam. When combined with the technique of conjugate readout, this device allows a lens-less data path and a very compact, self-aligning integration of the memory module. We also describe two neural arrays, using self-electro-optic-effect devices bonded to a silicon integrated circuit, and light-emitting diodes grown on a commercially processed gallium arsenide integrated circuit.

Finally, at the system level, we describe several integrated system architectures for holographic information storage and processing based on conjugate readout and the aforementioned device. We formulate storage density and cost projections. We report on laboratory prototypes of integrated modular holographic memory. Dynamic holograms were sustained over 50 refresh/decay cycles. Experimental data is presented.

Thesis Files