Electro-optic applications of ferroelectric liquid crystals to optical computing

Abstract

The surface-stabilized ferroelectric liquid crystal (SSFLC) electro-optic device is superior in many regards to other available optical and electro-optical switching devices for optical computing applications requiring the parallel operation of a large number of elements. The SSFLC device's large interaction with light, stemming from its large permanent birefringence, allows individual electro-optic elements to be small in size and hence allows the fabrication of many-element arrays on substrates of size convenient for optical systems. Further, its low switching energy allows these dense arrays to be operated at high speeds without unmanageable power dissipations, while its bistability allows its use as a high speed memory. We examine the fundamental physical limitations to the performance of the SSFLC device in parallel applications, and show that million element devices with microsecond switching times are feasible, allowing terabit/second data throughput rates. We also present prototype optical logic gates that represent their binary values with the two orthogonal components of linearly polarized light. Although these prototype optical logic gates are electrically addressed, we show how simple, sensitive optically addressed devices that retain the FLC's speed can be made with amorphous silicon photosensitive layers.