Accession Number : AD0841081

Title :   A WIDE-BAND OPTICAL CORRELATOR AND MATCHED FILTER USING DIFFRACTION OF LIGHT BY ULTRASONIC WAVES.

Descriptive Note : Research rept. Sep 67-May 68,

Corporate Author : NAVAL UNDERSEA WARFARE CENTER PASADENA CA

Personal Author(s) : Squire, W. D. ; Alsup, J. M.

Report Date : MAY 1968

Pagination or Media Count : 28

Abstract : An opto-acoustic device is proposed that can serve either as a correlation detector or a matched filter, and has a nominal bandwidth of 500 MHz and a time-bandwidth product of several thousand. The device consists of a pair of small (5-by-5-by-20-mm) microwave acoustic cells in close juxtaposition, which successively modulate a laser beam incident at the Bragg angle. This modulated light is focused to a point on a photodetector. The output of the photodetector represents the correlation function or matched-filter output for electrical signals that generate the acoustic disturbances in the two cells. An analysis of the device is presented and the derivation of its performance characteristics is described. Completed laboratory experiments that demonstrate feasibility are described and some of the engineering problems anticipated in developing an operational unit are discussed. (Author)

Descriptors :   *OPTICAL EQUIPMENT), (*CORRELATORS, (*MATCHED FILTERS, OPTICAL EQUIPMENT), ULTRASONIC RADIATION, LASERS, MODULATION, DIFFRACTION, DETECTORS, BANDWIDTH, FREQUENCY, RESOLUTION, DOPPLER SYSTEMS, SIGNALS, PROCESSING.

Subject Categories : Electrical and Electronic Equipment
      Acoustics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE