A Correct Way to Model Arbitrary Complex Distributed FeedBack (DFB) Lasers in The Above Threshold Regime

Abstract

Most of the published papers on the above-threshold simulation for DFB lasers utilize the powerful transfer matrix method (TMM) to include the longitudinal variations of the carrier and photon profiles caused by spatial hole burning and gain saturation effects at high output power[1]-[7]. However the approaches used to calculate the above-threshold behaviors were not correct. The most general mistakes are: (i). The use of the wrong threshold condition for the lasing mode both at and above threshold[2]- [5],[7] (ii). The iteration algorithm used to solve the above-threshold behavior for higher order DFB modes did not include the influence of the lasing mode properly[1],[2],[4],[5],[7].