Carrier diffusion and higher order transversal modes in spectral dynamics of the semiconductor laser

The dynamic and spectral behavior of the semiconductor stripe laser has been investigated. For this purpose the rate equations have been generalized to include several longitudinal and transversal modes, spontaneous emission into the active modes, and position dependence of the electron density through a term describing the charge-carrier diffusion in the plane of the active layer. The parameters used for solving these equations are found by theoretical and experimental considerations. The results show a broadening of the spectrum together with a significant content of higher order transversal modes along the junction plane.