An Experimental Optical-Fiber Link for Low-Bit-Rate Applications

An Experimental Optical-Fiber Link for Low-BitRate Applications By W. M. MUSKA (Manuscript received July 15, 1976) The design, construction, and performance of a practical optical link with interface circuits for coding and decoding 1.5-Mb/s, bipolar, digital signals are described. The optical devices used are light-emitting diodes and PIN photodiodes. A feedback or "transimpedance" preamplifier that incorporates a silicon junction-field-effect transistor is used in the receiver, which has a sensitivity of --57.2 dBm average optical power for a 10~9 bit-error-rate. The receiver demonstrates an optical power dynamic range of about 28 dB without requiring automatic gain control. Timing recovery is accomplished by a simple, conventional technique.