HIGH PERFORMANCE PHASED ARRAY SLOW SHEAR TeO2 BRAGG CELLS

Period of Performance: 06/28/1990 - 06/28/1992

$291K

Phase 2 SBIR

Recipient Firm

Photonic Systems, Inc.
1800 Penn St Suite 48
Melbourne, FL 32901
Principal Investigator

Abstract

TELLURIUM DIOXIDE (TeO2), ALSO KNOWN AS PARATELLURITE, IS AN UNUSUAL ACOUSTO-OPTIC MATERIAL IN THAT THE QUASISHEAR ACOUSTIC MODE IN THE [110] DIRECTION HAS AN ACOUSTIC VELOCITY AN ORDER OF MAGNITUDE LOWER THAN THAT FOUND IN OTHER ACOUSTO-OPTIC MATERIALS. VERY LONG TIME APERTURE DEVICE ARE POSSIBLE WITH THIS MODE, MAKING IT AN IMPORTANT DEVICE FOR ACOUSTO-OPTIC CORRELATOR AND HIGH RESOLUTION SPECTRUM ANALYZER APPLICATIONS. IN THE PHASE I PROGRAM WE SHOWED THAT IMPROVEMENTS IN SLOW SHEAR TeO2 BRAGG CELL DYNAMIC RANGE WERE POSSIBLE THROUGH THE USE OF A PHASED ARRAY TRANSDUCER. IN PARTICULAR WE SHOWED THEORETICALLY AND CONFIRMED EXPERIMENTALLY THAT A PHASED ARRAY TRANSDUCER DESIGN CAN ACHIEVE HECHT LIMITED DYNAMIC RANGE PERFORMANCE OVER A 50 us TIME APERTURE. WE PROPOSE TO BUILD ON THIS INITIAL EFFORT BY INVESTIGATING FURTHER BRAGG CELL PERFORMANCE IMPROVEMENTS, PARTICULARLY WITH REGARD TO DIFFRACTED OPTICAL BEAM QUALITY, BY MODIFYING THE PHASED ARRAY TRANSDUCER AND BY MODIFYING THE SLOW SHEAR TeO2 CRYSTAL ORIENTATION. SINCE THE DEMANDS ON OPTICAL BEAM QUALITY DIFFER FROM ACOUSTO-OPTIC CORRELATOR AND SPECTRUM ANALYZER APPLICATIONS, BRAGG CELL DESIGNS OPTIMIZED FOR EACH OF THESE WILL BE DEVELOPED.