Coupled-power theory of nonlinear distributed-feedback lasers, yielding reduced longitudinal spatial hole burning

Abstract

The authors present an analysis of the nonlinear distributed-feedback (DFB) laser action, derive a set of nonlinear coupled-power equations, and obtain a general condition for a nonlinear DFB laser with reduced spatial hole burning (SHB). It is found that the elimination of SHB in DFB lasers can be achieved by introducing properly chosen variations of the coupling strength along the longitudinal direction. On the basis of this, a novel complex-coupling AR-coated DFB laser diode is proposed.