FM and FSK Response of Tunable Two-Electrode DFB Lasers and Their Performance with Noncoherent Detection.

Two-electrode DFB lasers show promise for combining high speed and frequency tunability for FDM-FSK networks. We have measured the FM and FSK response of such lasers up to modulation frequencies of ~1 GHz. Using these lasers in a noncoherent detection system in which a fiber Fabry-Perot tunable optical filter converts an FSK signal into ASK format, we demonstrate 10 sup (-9) BER up to 1 Gb/s. Nonuniform FM response and consequent tone broadening of the optical FSK spectra can lead to system power penalties due to optical-filtering effects. Thus, for a given FM response, we can project the behavior of these lasers in FSK optical systems.