Threshold analysis of circular grating DBR/DFB lasers with lambda/4 phase-shift

In this paper threshold analysis for circular grating DBR/DFB with (lambda) /4 phase-shift lasers is presented. In particular, the influence of the phase-shift position in grating on the spectrum of the laser modes and gain is analyzed. It is shown that for central perturbation of the grating the mode selection is enhanced remarkably with comparison to laser structure with uniform grating, when the ratio of active medium length to the grating length is small.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.