Threshold analysis of phase-shifted distributed feedback lasers

Optimum structure parameters in phase-shift (PS) distributed-feedback (DFB) laser diodes are determined in order to ensure an emission with high mode selectivity, zero-frequency detuning and an almost uniform field distribution. In the present paper we analyze several multiphase shifted DFB structures using the transfer matrix method (TMM). The results allow the comparative analysis of single and multi-phase shifted DFB lasers in the near threshold regime, regarding their typical figures of merit, and will conclude about the main features associated with either the corrugation (coupling coefficient, length, ...) or the phase-shift discontinuities (amplitude, location).