Detuned-loading effect in fiber Bragg grating semiconductor lasers

Fiber Bragg grating semiconductor lasers (FGSLs) are interesting laser sources for WDM and many other applications. Dispersive fiber grating together with a laser diode chip form a complex cavity and can lead to many interesting phenomena. We have found that a discrete mode hop associated with an increase of the injection current can lead to a decrease of the relaxation oscillation frequency. The experimental observation and the theoretical explanation are reported in this paper.