Patent ID: 7907651

Claim:
A laser diode comprising: an active layer between a first semiconductor layer and a second semiconductor layer, a projecting part of the second semiconductor layer being between two groove-like concave parts, wherein an angle (θg) between said projecting part and one of the groove-like concave parts is 0.3° to 20°, said groove-like concave parts extending in a resonator direction (A) along a total length (L) of the projecting part, wherein a width (Wgf) of the groove-like concave parts is in the vicinity of said main-emitting-side end face of the laser diode, a width (Wgm) of the groove-like concave parts being between an opposite-side end face of the laser diode and said main-emitting-side end face, wherein a width (Wem) of said projecting part throughout said total length (L) is uniform, said width (Wgf) being 0.1% to 10% of the width (Wem).