Abstract

Computer-generated holograms (CGHs) have traditionally been employed mostly for optical testing of aspherics. Their applications have recently been expanding to many new areas where the equivalent optical holograms are difficult to make. For example, in wavefront/beam conversion, CGHs can convert Gaussian beams to uniform beams or uniform beams to nondiffracting beams. For pattern recognition, CGHs are designed to make geometric transformations or to perform synthetic spatial filtering functions. For optical interconnects, CGHs are synthesized to distribute clock signals to various parts of a VLSI wafer, to power up an array of multiple-quantum-well optical bistable devices, or to facilitate intercommunication among multiprocessors and shared memories for optical digital computing. Furthermore, CGHs can be fabricated to combine the functions of multiple optical elements to reduce the size and weight of optical pickup heads for improved access speed in optical storage systems. CGHs can be fabricated on the flat surfaces of refractive optics to reduce aberrations and broaden their spectral responses, consequently reducing the number of refractive elements in achromatic optical systems. They can also be produced on the posterior surface of an intraocular lens to provide bifocal vision. Many of these recent advances have been facilitated by improved fabrication tools such as the electron beam writer and the reactive ion beam miller, and by improved CGH design procedures.

© 1989 Optical Society of America