IN FIBER OPTIC SYSTEMS

THE EXPANDING FIBER OPTIC SENSOR FIELD HAS POINTED TO INCREASING NEED FOR SUITABLE COMPACT, EFFICIENT, AND REASONABLE COST INTERFACE SUBASSEMBLIES. IN PARTICULAR, SPECTRAL ANALYZERS ARE NEEDED TO INTERPRET THE FIBER OPTIC SIGNAL FROM AN OF NUMEROUS TYPES OF FIBER SENSORS -- E.G., WAVELENGTH MODULATION SENSORS. A VERY PROMISING TYPE OF SPECTRAL ANALYZER FOR THIS PURPOSE IS A "HOLOGRAPHIC PROCESSOR". A PATENT ON THIS BASIC DEVICE WAS GRANTED IN 1981. PHASE I OF THIS PROGRAM CONSIDERS THE TRADEOFF OF EFFICIENCY, BANDWIDTH, AND SENSITIVITY IN APPLYING THE HOLOGRAPHIC PROCESSOR TO TYPICAL REQUIREMENTS FOR OPTIC SYSTEMS. IT ALSO CONSIDERS THE POSSIBILITY OF COMBINING THE TECHNIQUE OF SINGLE-EXPOSURE HOLOGRAMS, USED OVER A RANGE OF BANDWIDTHS ABOUT THE EXPOSURE WAVELENGTH, WITH THE TECHNIQUE OF MULTIPLE-EXPOSURE HOLOGRAPHY. A SINGLE EXPOSURE HOLOGRAM IS THEN CONSTRUCTED FOR USE IN A TYPICAL FIBER OPTIC SENSOR ALREADY DEVELOPED BY OPCOA FOR NASA.