Semiconductor laser device

A semiconductor laser device in which a semiconductor layer, a dielectric film, and an electrode layer are stacked in this order,

• wherein the semiconductor layer is formed by stacking an n-type clad layer and a p-type clad layer in this order, and includes
• a ridge formed on the p-type clad layer and extending from one end to an other end in a direction laterally traversing the semiconductor layer, when viewed in a plan view,
• two first recesses, each of which is formed on both sides of the ridge along the laterally traversing direction,
• two groove-shaped second recesses having a depth reaching the n-type clad layer from the p-type clad layer and extending from each end in a direction longitudinally traversing the semiconductor layer to positions where the ridge is interposed between the two groove-shaped second recesses, when viewed in a plan view, and
• two groove-shaped third recesses having a depth reaching the n-type clad layer from the p-type clad layer, extending from the one end in the direction laterally traversing the semiconductor layer toward the second recesses in the laterally traversing direction when viewed in a plan view, and disposed at positions where the ridge is interposed between the two groove-shaped third recesses in the longitudinally traversing direction,
• the dielectric film covers at least a surface of the semiconductor layer other than the ridge, and
• the electrode layer overlaps the ridge and overlaps the dielectric film on an other end side from the second recesses in the laterally traversing direction when viewed in a plan view.