SURFACE ACOUSTIC WAVE DEVICE FOR WIDE ANGLE LASER SCANNING

LASER BEAM SCANNING IS REQUIRED TO SUPPORT SPACECRAFT TERMINAL RENDEZVOUS, STATION-KEEPING, AND DOCKING. CURRENTLY, ACOUSTO-OPTIC BRAGG CELLS OFFER THE BEST AVAILABLE MEANS OF SCANNING A LASER BEAM WITHOUT USE OF MOVING MECHANICAL PARTS. BRAGG CELLS, HOWEVER, ARE LIMITED BY THEIR SMALL ANGULAR RANGE, LOW SCAN SPEED, AND HIGH POWER REQUIREMENTS. WE THEREFORE PROPOSE AN ADVANCED INTEGRATED ACOUSTO-OPTIC LASER SCANNER WHICH WILL LARGELY OVERCOME THESE LIMITATIONS. OUR PROPOSAL INTRODUCES SEVERAL INNOVATIONS. FIRST, WE PROPOSE USING MICROWAVE FREQUENCY (1-3 GHZ) SURFACE ACOUSTIC WAVES (SAWS) ON PIEZOELECTRIC THIN FILM AIN WAVEGUIDES WITH BROADBAND BRAGG PHASE MATCHING TO INCREASE THE FIELD OF VIEW AND IMPROVE THEOVERLAP BETWEEN ACOUSTIC AND OPTICAL GUIDED WAVES. SECOND, WE PROPOSE CASCADING OF SAW GRATINGS TO FURTHER INCREASE THE FIELD OF VIEW. THIRD, WE PROPOSE USING A PHASE-LOCKED DIODE LASER ARRAY TO PROVIDE HIGH OPTICAL POWER (WATTS) WITHOUT THE NEED FOR A PRISM COUPLER OR WAVEGUIDE COLLIMATING LENS. LASTLY, WE NOTE THAT USING HIGH SPATIAL FREQUENCY SAW GRATINGS MAY ADMIT THE POSSIBILITY OF EFFICIENTLY DEFLECTING LIGHT OUT OF THE PLANE FOR TRUE TWO-DIMENSIONAL SCANNING. IN PHASE I, WE PROPOSE TO ANALYZE THE SAW LASER SCANNER CONCEPT AND TO EXPERIMENTALLY DETERMINE ACOUSTIC POWER REQUIREMENTS FOR EFFICIENT DEFLECTION OF AN ALGAAS LASER BEAM.