Low noise 100 Mbit/s optical receiver

A stable, low noise and wide band optical receiver using an avalanche photo-diode (APD) and bipolar transistors has been realized and successfully applied to a 100 Mbit/s compact optical repeater. The front end of this receiver is a simple common-emitter circuit with collector peaking, which is shown theoretically and experimentally to be better than feedback type or high impedance (FET) type. The error rate of less than 10 to the -9th at average optical input power of -48dBm and the maximum repeater spacing of 7 km for 5 dB/km graded index fiber have been achieved. The repeater size is 170x75x45 mm and the power consumption is about 4.2 W.