Semiconductor laser device

Abstract

A semiconductor laser device has stabilized longitudinal and transverse modes without excess optical noise for a modulated signal generated by mode interaction. The fundamental construction of the semiconductor laser device comprises a structure wherein a first semiconductor layer is sandwiched between second and third semiconductor layers which have a greater band gap and lower index of refraction than the first semiconductor layer. That region of at least one of the second and third semiconductor layers which is remote from the first semiconductor layer corresponds substantially to a radiation region and serves as a light non-absorptive region in the shape of a stripe. A semiconductor layer has portions lying on both sides of the semiconductor layer remote from the first semiconductor layer and has an effective complex refractive-index for laser light discontinuous at both ends of the semiconductor layer remote from the first semiconductor layer. Periodic corrugations which intersect orthogonally to the lengthwise direction of the stripe-shaped light non-absorptive region are formed in at least one interface of the semiconductor layers in a manner to include at least a region corresponding to the light non-absorptive region.