Theoretical analysis of the longitudinal mode behavior due to mode competition in bulk semiconductor lasers

Abstract

The following typical longitudinal mode phenomena occur in bulk semiconductor lasers: single-mode or multimode operation for longitudinal modes, longitudinal mode suppression except for a dominant mode, asymmetry of the spectral profile of longitudinal modes, mode hopping, and dominant mode hysteresis. This article presents the theoretical occurrences of these phenomena in a unified manner by solving mode-competition equations, including nonlinear gain based on the density matrix method. We select various types of bulk semiconductor lasers for theoretical analyses, including an 850 nm GaAs material, 1.3 and 1.55 µm InGaAsP materials, and wide-striped and narrow-striped structures of an active region. These unified analyses reveal the main factors of these phenomena and the physical parameters that influence these phenomena. A good understanding of these physical parameters will help in designing bulk semiconductor lasers with the desired characteristics.