Semiconductor laser and semiconductor laser module

Abstract

The present invention provides a semiconductor laser capable of performing high-speed modulation and having a low-capacity structure. The semiconductor laser comprises a semiconductor substrate, a multilayered growth layer which is formed on the main surface side of the semiconductor substrate in multilayer form and which is electrically isolated from the semiconductor substrate and includes, in a middle layer, an active layer interposed between a semiconductor layer of first conductivity type corresponding to a lower layer and a semiconductor layer of second conductivity type corresponding to an upper layer, a ridge formed between two trenches, which is provided on the surface of the multilayered crystal layer without reaching the active layer, a first isolation trench which is provided outside the trench located on one or other side of the ridge along the ridge and reaches a semiconductor layer below the active layer, and a second isolation trench which reaches a surface layer of the semiconductor substrate, an insulating film formed on the main surface side of the semiconductor substrate except for the upper surface of the ridge, a second electrode whose part contacts the second conductivity type semiconductor layer on the upper surface of the ridge and which extends onto the insulating film beyond the second isolation trench, and a second electrode which deviates from above the ridge and is formed on the insulating film on the first isolation trench side and whose part contacts the first conductivity type semiconductor layer located below the active layer.

Dependencies are inferred from the claim text.