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 .