Abstract

The phase conjugation property of backward-stimulated photon echo (BSE) has numerous potential applications in optical data storage and processing. We demonstrate mixed binary multiplication of spatially encoded bit patterns, by taking advantage of the fact that the geometry of BSE is analogous to that of conventional holography or four-wave mixing of nonlinear optics, where an object (data) and a reference (write) beams interfere to create a grating inside the medium, and another reference (read) beam is diffracted from that grating. When all three input beams contain structures, the output pattern is the convolution and correlation of the input patterns, which, with certain arrangements and interpretation, can be used for multiplication of binary numbers. The experiments were done by using a 477.8 nm transition of praseodymium ion-doped in single-crystal lanthanum trifluoride.

© 1990 Optical Society of America