Vol. 31, Issue 2, pp. 351-371 (2001)

Abstract

A threshold analysis is presented for circular grating distributed feedback (CG-DFB) and circular grating distributed Bragg reflector (CG-DBR) lasers with additional phase shift introduced in the grating region. It is found that the proper value and position of the additional phase shift reduces the threshold gain of the laser structure and also improves its mode selectivity.