Optical information processing

TL;DR: In this paper, a read-write holographic memory was proposed, which combines a two-dimensional layered architecture and holography, and the performance of both sensors was theoretically modeled and experimentally verified.

Abstract: The title of this work Optical Information Processing reflects the multi-facets of this thesis. In the first three chapters, I look at specific aspects of optical data storage. Enabled by new recording materials, a read-write holographic memory is explored. The memory combines a two-dimensional layered architecture and holography. Recording dynamics are analyzed and compared with conventional memories. A novel multiplexing method, based on the confinement of spherical waves in waveguides, allows the implementation of fiat read-only memories with no moving parts. Novel polymer films at low temperatures show extremely selective frequency absorption which yields up to hundred thousands of independent frequency channels. This radically different multiplexing scheme is combined with Bragg multiplexing to increase the storage density. Femtosecond pulses can be stored and retrieved in these materials. For further processing, a pulse shaper and an all-optical logic capable of processing Terahertz pulse streams are experimentally demonstrated. The last two chapters look at three-dimensional surface measurements. A profilometer and a wavefront sensor based on the propagation of light in birefringent crystals are investigated. The performance of both sensors is theoretically modeled and experimentally verified. A third sensor is designed for an ophthalmic application.