Abstract

Optical FDM and FSK systems require frequency tunable lasers with large and flat FM response magnitude and phase. Such lasers include frequency tunable two-electrode DFB lasers,¹ which have been used recently in FSK based communcation systems.² These lasers with two active sections have a larger FM bandwidth than tunable three-electrode DBR lasers with a modulated passive section, where the modulation rate is limited to ~200 Mbit/s.³ We characterized two-electrode DFB lasers for use in FSK systems by measuring the FM response magnitude and FSK spectra at various modulation rates. We subsequently relate these characteristics to bit-error-rate (BER) measurements in a noncoherent detection communication system in which the FSK signal is converted to an ASK format by an optical filter.⁴ Thus we relate directly basic device characteristics of these lasers to system performance.

© 1990 Optical Society of America