A field demonstration of 1.7 Gb/s coherent lightwave regenerators

Four 1.7-Gb/s frequency-shift keying (FSK) coherent regenerators that were successfully operated in a typical field environment using installed fiber cables connected between Roaring Creek and Sunbury, PA (a distance of 35 km) are discussed. Each regenerator is housed in a standard AT&T repeater shelf and consists of five separate plug-in subsystem modules including a polarization diversity receiver, a FSK transmitter, and a cold-start automatic frequency control (AFC) circuit. During one month of continuous operation, the received optical powers for 10/sup -9/ bit error rate (BER) were between -38 and -40 dBm. An error rate below 6*10/sup -15/ (less than one error per day) was achieved at received optical powers of -33 approximately -35 dBm. >