TERRACED-SUBSTRATE GAAS-(GAAL)AS INJECTION-LASERS

A new structure of stripe-geometry lasers has been reported in which a double heterostructure is fabricated on a terraced substrate. Due to the lateral change of the effective refractive index along the junction plane, the optical gain distribution is restricted within a narrow stripe between two adjacent bends of the active layer regardless of the current spreading. This simple structure constantly exhibits a fundamental longitudinal mode oscillation as well as a single transverse-mode oscillation. No kinks have been observed in light-output-current characteristics. The linearity continues up to 10 times the threshold where the power output is 150 mW/facet.