Gain Saturation Effect of Photon and Carrier Density Transverse Distributions in a Semiconductor Injection Laser

Abstract

We derive more general photon and carrier density distributions along two transverse directions in a semiconductor injection laser, by considering the fact that the carrier density is reduced by lasing along the direction parallel to the direction of injection current and that the photons are not totally confined in the active layer. It is shown that the photon and carrier density distributions along the direction parallel to the injection current direction have negligible effect on gain saturation, not due to the small thickness of the active layer but due to the distribution pattern. It is also shown that the photon and carrier density distributions along the direction perpendicular to the injection current direction cause small gain saturation which agrees to the result of previous model obtained by confining all the photons to the active layer.