Optical autodyne detection: theory and experiment.

Optical autodyne detection is a direct detection procedure for measuring relative Doppler frequency shifts using a laser transceiver. A theoretical study of the carrier-to-noise ratio and signal-to-noise ratio for an autodyne transceiver is presented. Experimental results, obtained with a cw autodyne transceiver, are reported. The relative merits of optical autodyne vs optical heterodyne detection are discussed.

Role of photodetectors in optical signal processing.

Optical signal processing applications place demands on photodetector arrays beyond those encountered in image sensing applications. We review the basic requirements and show that increased dynamic range and nonlinear decision operations that lead to reduced output data rates are the key improvements needed for both 1-and 2-D arrays. Arrays of high-speed photodetector elements with integrated postdetection circuitry are also needed. Although we suggest some possible methods for achieving these goals, our main objective is to stimulate the photodetector community to design and fabricate more useful devices.