IMAGING SPECTROMETER USING THE ACOUSTO-OPTIC TUNABLE FILTER

WE PROPOSE TO DEVELOP AN IMAGING SPECTROMETER BASED ON THE ACOUSTO-OPTIC TUNABLE FIBER (AOTF) COUPLED TO INFRARED ARRAY DETECTORS FOR INFRARED SIGNATURE MEASUREMENTS OF LOW-OBSERVABLE AIRCRAFT. THE AOTF IS A MINIATURE, HIGH SPEED, AND RUGGED DEVICE MADE FROM BIREFRINGENT CRYSTAL SUCH AS TEO2, AND CAPABLE OF TRANSMITTING A SPECTRAL IMAGE. DURING PHASE I, WE WILL MODIFY AN EXISTING AOTF SPECTROMETER WE HAVE DEVELOPED TO ADD IMAGING CAPABILITY. THIS IMAGE WILL BE FOCUSED ONTO A CCD CAMERA FOR THE PHASE I FEASIBILITY STUDIES IN THE NEAR-INFRARED. THE AOTF DEVICE WILL BE OPTIMIZED FOR IMAGING BY INCREASING THE ACCEPTANCE ANGLE AND ACTIVE APERTURE OF THE DEVICE. WE WILL DETERMINE THE PERFORMANCE OF THE SYSTEM BY MEASURING THE SPECTRAL AND SPATIAL RESOLUTION, SPEED AND WAVELENGTH RANGE. WE WILL USE THIS SYSTEM TO SCAN THROUGH THE ABSORPTION BANDS OF TEST SAMPLES. DURING PHASE II, THE AOTF WILL BE FURTHER IMPROVED, AND THE SPECTRAL RANGE WILL BE EXTENDED TO LONGER WAVELENGTHS BY USING OTHER CRYSTAL MATERIALS AND INFRARED FOCAL PLANE ARRAY DETECTORS OR CONVENTIONAL THERMOGRAPHIC CAMERAS. IN ADDITION, WE WILL DEVELOP HIGH SPEED DATA ACQUISITION HARFWARE AND SOFTWARE TO CONTROL THE AOTF AND PROCESS THE DATA.