PASSIVE AGILE LASER FILTERS

PHYSICAL OPTICS CORPORATION PROPOSES TO DEVELOP BROADBAND LASER FILTERS WHICH OPERATE IN THE VISIBLE REGION OF THE SPECTRUM (400 - 700 NM), DO NOT REQUIRE ANY EXTERNAL BIASING (THERMAL OR ELECTRICAL) OR A FOCAL PLANE, AND WHICH CAN BE USED OVER RELATIVELY LARGE AREAS (100 CM[2]). THE FUNDAMENTAL APPROACH USES A BACK PROPAGATING SELFINDUCED BRAGG STRUCTURE THAT IS HIGHLY REFLECTIVE TO ANY LASER FREQUENCY IN THE VISIBLE AND NEAR IR REGION OF THE SPECTRUM. THESE FILTERS WILL REPRESENT A NEW GENERATION OF HOLOGRAPHIC BRAGG REFLECTION FILTERS WHICH CREATE THEMSELVES AT THE THREAT WAVELENGTH BUT REMAIN TRANSPARENT TO OTHER PORTIONS OF THE SPECTRUM AND SUBSEQUENTLY ERASE THEMSELVES WHEN THE THREAT GOES AWAY. THUS, IN ADDITION TO HAVING ALL OF THE ADVANTAGES OF CONVENTIONAL HOLOGRAPHIC FILTERS, THIS AGILE FILTER WILL ALSO POSSESS THE UNIQUE FEATURE OR REFLECTING LASER BEAMS WHILE BEING HIGHLY TRANSMISSIVE TO AMBIENT ILLUMINATION. THESE NEW FILTERS CAN BE EXPECTED TO HAVE A HIGH PHOTOPIC TRANSMISSION (70% OR GREATER) WHILE PROVIDING PROTECTION AGAINST BOTH PULSED AND CONTINUOUS WAVE LASERS AS THE FILTER WILL HAVE RESPONSE TIMES ON THE ORDER OF PICOSECONDS.