Investigations of Fiber Optic Delay Line Signal Processors and a Fiber Optic Intrusion Sensor System.

Abstract : A programmable fiber optic delay line using optical switches, a fiber optic delay line sequence generator, and a distributed fiber optic intrusion sensor were investigated. The programmable delay line is based upon a network of all-fiber switches connected by fibers of different lengths. The switches showed an unprecedented combination of low insertion loss, polarization independent operation, and fast switching. A 4-stage system with 16 different programmable delays was constructed. The sequence generator consists of a laser which injects optical pulses into a network of 2x2 fiber couplers connected by filters of different length. Unipolar and bipolar sequences were generated at Gbit/sec rates. The intrusion sensor system analyzed in this report is intended to detect, locate, and classify intruders over long perimeters. A range of 28 km for 100 m range resolution is predicted.