A cold-start 1.7 Gb/s FSK heterodyne detection system using single-electrode DFB lasers with no equalization

A cold-start, 1.7-Gb/s frequency-shift keying (FSK) heterodyne single-filter detection system using ordinary single-electrode distributed feedback (DFB) lasers is discussed. These lasers were frequency-locked to an atomic krypton line at 1.5224 mu m independently. Thus, this system can maintain a constant IF without an IF locking circuit and consequently does not require any IF acquisition circuitry for cold-start operation. The measured receiver sensitivity of this system was -41 db (1 mW) at an error rate of 10/sup -9/.<
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