Yield analysis of second-order DSM DFB lasers and implications for design

The results of yield analysis of dynamic single-mode (DSM) second-order distributed feedback (DFB) lasers are presented. Design implications of this analysis are discussed. Three ways of achieving DSM operation which, depending on the design, can operate simultaneously are considered: radiation loss, asymmetric end cavity reflections, and phase shifting of a grating. The interplay among these mode selection mechanisms is analyzed under conditions of random facet cleaving. The calculated expected yield is subjected to three constraints: a minimum side-mode suppression ratio, a maximum threshold current, and a minimum external quantum efficiency. A comparison of DSM performance between first-order and second-order DFB lasers of analogous designs is also included.