Analytical derivation of the structure of carrier lifetime and its nonlinear dependence on optical field intensity in semiconductor laser structures

The dependence of spontaneous carrier lifetime τs on the electromagnetic field in the laser cavity is discussed in the framework of a microscopic approach to laser dynamics. An analytical relationship between τs and the number of photons in the laser cavity is derived. The structure of τs suggests new experiments for the determination of microscopic parameters of the active region material (e.g., the intraband carrier lifetime τ_in). This relationship is nonlinear and does not exhibit any kind of singularity or discontinuity, as sometimes reported in the literature. The comparison between theory and experimental results is discussed.