Optical-fiber delay line devices offer great potential1 for the processing of broadband signals due to the large modulation bandwidth and low loss of the optical fiber itself, which for the case of single-mode fiber can have values of the order of 100 GHz-km and fractional dB/km, respectively. Signals to be processed are intensity modulated onto optical carriers, and the processed output signals are obtained by detection after the optical signals traverse the optical fiber circuitry. This paper is intended to provide a general overview of the elementary forms of fiber circuitry that are useful for signal processing as well as the complex filters and systems that they Gan be used to construct.