Gain broadening mechanism in various GaAlAs laser structures

Abstract

Coupling of an external grating to a GaAlAs laser results in a strong enhancement of the selected mode and a reduction of the nonselected modes. The spectral form of this reduction is measured with a new sensitive experimental arrangement for three types of laser structures: proton bombarded stripe geometry, V‐groove and CSP lasers. This spectral form is determined by the gain curve of the laser only and is independent on the position of the selected mode, i.e., no spectral hole burning is observed at room temperature.