Studies on the Effective Physical Parameters for Chirp Reduction in Optical Injection Locked Semiconductor Lasers

Abstract

In optical injection locking, the light from one laser (master laser)is injected into another laser slave laser. The injected light causes changes in the slave laser characteristics, and it can lock the slave laser lasing frequency to the ML lasingfrequency. The locking characteristics are determined by theamount of injected power and thefrequency difference between the master laser and slave laser.In this paper, the chirp of injection-locked semiconductor lasers has been theoretically investigated. First, chirpcharacteristics of semiconductor lasers are described. The chirp to power ratio has been calculated with including opticalinjection effect in lasers rate equation. Then, the effects of phase difference between master and slave laser and modulation frequency on chirp to power ratio are evaluated. The results of calculations show that the effect of phasedifference can be neglected, but optical injection, line width enhancement factor, and detuningfrequency have an effective role in chirp reduction of semiconductor lasers.