Modeling of distributed feedback semiconductor lasers with axially-varying parameters

Abstract

We describe a numerical model that is capable of predicting important laser characteristics such as the threshold gain and the gain margin between the main and side modes for a distributed feedback (DFB) semiconductor laser of arbitrary complexity. The method consists of solving the coupled-mode equations with axially-varying parameters iteratively until the boundary conditions at the two facets are satisfied. We apply the numerical model to discuss two DFB laser structures. In the case of a multiple-phase-shift DFB laser our results show that such devices can have a more uniform axial distribution than that of a conventional quarter-wave-shifted DFB laser while maintaining sufficient gain margin between the main and side modes. In the case of a dual-pitch DFB laser we show that the incorporation of a slightly different grating period ( -0.1 percent) over a small section can provide a gain margin that is comparable to that achieved in quarter-waveshifted DFB lasers.

Numerical study of three phase shifts and dual corrugation pitch modulated (CPM) DFB semiconductor lasers based on reconstruction equivalent chirp technology

“…According to the double phase shifts DFB LD [12,13], when each of the two phase shifts is about 5π/18, it has the largest threshold gain margin. So in our design, the dual CPM structure is designed to obtain an arranged phase shift of 5π/18 in each PAR.…”

“…Single longitudinal mode (SLM) operation is often restricted to the vicinity of threshold [8]. Therefore, some methods were proposed to reduce the SHB, such as multiple phase shifts structure [12,13] and corrugation-pitch modulation (CPM) structure [14,15]. But the fabrication of these complex structures requires a precision control of each grating line.…”

Thermal Characteristics of Temperature Sensor Using Fiber Bragg Grating for Optical Sensor Network Communication

“…Since (7a) and (7b) can then be solved analytically, the propagation through a subsection is carried out by using the prescription [11][12][13]. 11 12…”

A Rigorous, Coupled-Wave Transfer Matrix Method for Two-Dimensional Threshold Analysis of Distributed Feedback Semiconductor Lasers

“…Much of the work done up to the present time is based on the onedimensional theory, particularly in the more complicated cases of λ/4-shifted DFB lasers [6,7], DFB lasers with axially-varying parameters [8], and multielectrode DFB lasers. In addition, there is an enormous amount of work in which one-dimensional theory is used in nonlinear models of such effects as gain saturation, spectral and spatial hole-burning, filamentation and many others.…”