Gain Calculation of Undoped GaAs Injection Laser Taking Account of Electronic Intra-Band Relaxation

Abstract

The intra-band relaxation of electrons is a basic factor to be considered for the characterization of injection lasers, especially in the investigation of modal behavior under lasing operation. This paper discusses the gain and refractive index in quantitative terms and considers the intra-band relaxation phenomenon in undoped GaAs lasers. The linear and third order gain coefficients are summarized in arithmetic equations by numerical calculation. Some characteristic parameters in the equations are also confirmed experimentally through measurements of the output spectral profile and laser threshold. The results give a more consistent interpretation of non-oscillating and oscillating states than previously-established theories, which do not take into account the intra-band relaxation.