A Cold-Start 1.7-Gbit/s FSK Heterodyne Detection System Using Single-Electrode DFB Lasers with No Equalization.

We report a cold-start, 1.7-Gbit/s FSK heterodyne single-filter detection system using ordinary single-electrode DFB lasers. These lasers were frequency-locked to an atomic Krypton line at 1.5224microns independently. Thus, this system can maintain a constant IF without an IF locking circuit and consequently does not require an IF acquisition circuitry needed for cold- start operation. The measured receiver sensitivity of this system was -41 dBm at an error rate of 10 sup (-9).