The natural linewidth of Fabry–Perot semiconductor lasers; simulation of experiments

Abstract

A medium component of the natural linewidth of a Fabry-Perot semiconductor laser found by applying nonlinear photo-refractivity on laser frequencies is considered. The natural linewidth is calculated using a new formula for the line shape which has been derived from the application of nonlinear photorefractivity. Medium, phase, and amplitude components of the natural linewidth are taken into account. We have defined and found the numerical values of laser parameters which describe the natural linewidth of Fabry-Perot semiconductor lasers by solving an inverse problem, and we have simulated all the experimental measurements represented in the literature we have available.

On the nonlinear theory of Fabry–Perot semiconductor lasers

“…Formula for line shape outside the laser was derived in [3,4]; within the laser it has the following form:…”

“…Formulas for S 0 , S 1 and S 2 expressed in terms of the laser parameters are listed in paper [3]. Effective natural linewidth of the emission line is defined by the formula [2]:…”

“…We have simulated [2][3][4] 15 experiments on natural linewidth in FP lasers reported in literature [11][12][13][14][15][16], and have simulated [17,18] 15 experiments on that in DFB lasers reported in literature, based on the derived formulas of line shape (method 1 in [3,17]), and based on the derived formulas for natural linewidth (method 2 in [2,18]). Information about the experiments No.…”

“…Measurements of ν ∆ (1/P) for (GaAl)As laser at T = 273, 195 and 77 K are presented in figure 1 [11]; averaged experimental ν ∆ (1/P) for these experiments are presented in figure 1(A) [3] simultaneously with theoretical curves 2.…”

“…In this paper, we derive the gain g for a Fabry-Perot semiconductor laser based on the density matrix equations and expressions for the effective linewidth [2]. Thus, linewidth theory [2][3][4] is an integral part of the nonlinear theory. The resulting dependence of g on the energy flux has been called the main nonlinear effect in semiconductor lasers [5]; derivation of this relation formula is presented in sections 2 and 3.…”