Acousto-optic multiplexing and demultiplexing

Abstract

A system for multiplexing or demultiplexing pulsed laser radiation having an acousto-optical device which is electrically controlled to switch a common path of high pulse rate laser radiation between a plurality of spatially distinct paths for relatively lower pulse rate laser radiation at which the pulses are sequenced according to a predetermined time pattern. The acousto-optical element typically includes a Bragg cell which is electrically driven by a set of distinct frequencies, causing deflection of radiation passing therethrough at a predetermined set of angles whereby pulsed radiation on a single path may be distributed onto the plural separate paths or radiation on plural separate paths of time-sequenced pulses of radiation can be combined into a single path of augmented pulse rate. The control of the acousto-optical element may be provided by selectively switching the output of a plurality of fixed frequency oscillators of different frequency to the acousto-optical element in accordance with the pattern of pulses on the common or plural distinct paths or a voltage-controlled oscillator may be sequenced through a repeating set of frequencies which are sampled one or more times per sequence to develop an error signal resulting in feedback control over the oscillator to eliminate long-term drift.