ASK heterodyne receiver sensitivity measurements with two in-line 1.5 μm optical amplifiers

A heterodyne amplitude shift keying configuration was used to evaluate the performance of resonant-type optical amplifiers in a coherent lightwave communication system. With two in-line amplifiers, each with a gain of 25 dB, the total loss between the transmitter and the receiver was 95 dB at 10-9 bit error rate. At a 100 Mbit/s data rate, the receiver sensitivity without amplifiers was -49.3 dBm. With two amplifiers the receiver sensitivity could be maintained at -49.0 dBm.