Accession Number : ADD008585

Title :   Acoustooptic Time Integrating Frequency Scanning Correlator

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Berg,Norman J

Report Date : 06 Apr 1981

Pagination or Media Count : 21

Abstract : This abstract discloses an acousto-optic time integrating two-dimensional frequency scanning correlator for cross-correlating signals which are separated in frequency. Two coherent light beams which are derived from the same laser are fed across respective Bragg cells, one cell having the signal A(t) cos omega sub A t propagating thereacross and the other cell having the signal B(t) cos omega sub B t propagating thereacross. The respective output beams are comprised in the x direction and expanded in the y direction and are made incident on an acousto-optical correlator device having chirp signals counter-propagating thereacross. The optical output is fed to a time-integrating photodiode array which provides an output signal corresponding to the cross-correlation of A(t) and B(t). In a further embodiment, the two Bragg cells are replaced by a single Bragg cell and beams having different polarizations are fed thereacross. In a still further embodiment, only a single crystal is used which has the A(t) and B(t) signals, as well as the chirp signals, counter-propagating thereacross.

Descriptors :   *Patent applications, *Optical correlators, *Acoustooptics, Optical scanning, Bragg angle, Chirp filters, Two dimensional, Signal processing, Phase shift keyers, High pass filters, Spread spectrum

Subject Categories : Acoustooptic and Optoacoustic Devices
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE