Large carrier-effect red shift in lambda /4-shifted DFB lasers with in-phase complex gratings

Theoretical analysis of the wavelength tuning characteristics shows that the carrier effect in lambda /4-shifted DFB lasers with in-phase complex grating can produce a large red shift while maintaining stable singlemode operation. The FM response of these lasers can thus avoid having any dip at lower modulation frequencies, where the thermal red shift opposes the carrier blue shift of conventional lasers.<>