Short-term wavelength changes in 1.5-μm InGaAsP-InP distributed feedback semiconductor lasers

We report short-term lasing wavelength changes in 1.5-μm InGaAsP-InP distributed feedback (DFB) lasers. The lasing wavelengths after biasing the lasers have been changed upto 1.2 /spl Aring/ at 20/spl deg/C while maintaining the constant output power. It takes over 700-2000 s, to stabilize the lasing wavelengths in many lasers. The annealing effects could be partially responsible for the wavelength change. It certainly affects the initial performance of cold-start frequency-division-multiplexed systems.