TUNABLE IR DETECTOR

THE INCREASED SENSITIVITY ACHIEVED WITH INFRARED SOLID STATE PHOTOMULTIPLIER DETECTORS MAKE IT POSSIBLE FOR SENSORS TO OPERATE IN VERY NARROW WAVELENGTH INTERVALS. THE USE OF THESE NARROW BAND SYSTEMS HAS THE POSSIBILITY OF ACHIEVING ADDITIONAL SENSITIVITY WHEN OPERATED AGAINST ATMOSPHERIC BACKGROUNDS BY WORKING OVER SUCH NARROW SPECTRAL REGIONS THAT THE BACKGROUND RADIATION CAN BE SIGNIFICANTLY REDUCED. ACHIEVING SUCH A SPECTRAL NARROW BAND PASS WITH REASONABLE THROUGHPUT IS DIFFICULT PARTICULARLY WHERE THE "FILTER" HAS TO BE CRYOGENICALLY COOLED. FABRY-PEROT INTERFEROMETER SYSTEMS OFFER A POTENTIAL TECHNIQUE FOR ACHIEVING THE DESIRED SPECTRAL RESOLUTION IN AN OPTICAL CONFIGURATION THAT CAN BE COOLED. WE PROPOSE TO DESIGN A CONFOCAL FABRY-PEROT SYSTEM WHICH CAN BE TUNED AND CRYOGENICALLY COOLED.