TUNABLE NARROWBAND OPTICAL FILTERS FOR LIDAR

WE PROPOSE TO DESIGN TUNABLE NARROW BANDWIDTH OPTICAL FILTERS FOR USE IN DAYLIGHT LIDAR SYSTEMS. THESE FILTERS WILL SATISFY THE FOLLOWING DESIGN REQUIREMENTS: PICOMETER BANDWIDTH IN THE VISIBLE REGION; WIDE ANGULAR ACCEPTANCE (F/1); FAST RESPONSE 10%; STABLE, TUNABLE OPERATION; LOW BACKGROUND; AND STRAIGHTFORWARD, EFFICIENT COUPLING TO PHOTOMULTIPLIER. THE DESIGN WAVELENGTHS WILL BE THOSE OF INTEREST FOR RAYLEIGH, MIE, AND RESONANCE/FLUORESCENCE LIDARS. THE FILTERS WILL EXPLOIT GAS-PHASE ATOMIC ABSORPTIONS. THIS CHOICE AUTOMATICALLY SATISFIES THE FIRST THREE DESIGN REQUIREMENTS. THE CRITICAL TASKS OF THE PROPOSED RESEARCH WILL BE: IDENTIFYING SUITABLE ABSORPTION SPECIES; DESIGNING EFFICIENT, BACKGROUND-FREE TRANSFER MECHANISMS FOR RE-RADIATING THE ABSORBED ENERGY; DESIGNING A LOW-LOSS COUPLING TO PHOTOMULTIPLIER; AND SELECTING A TUNING MECHANISM.