| 摘要 |
A laser diode includes: a substrate; a semiconductor layer including a lower cladding layer, an active layer, and an upper cladding layer; a strip-shaped ridge provided on an upper cladding layer side in the semiconductor layer; and a pair of resonator end faces sandwiching the semiconductor layer and the ridge. The substrate includes strip-shaped grooves provided on both sides of a portion facing the ridge along the portion facing the ridge, and extending in a direction different from a direction orthogonal to the extending direction of the ridge, and L1, L2, and L3 satisfy the following relationship, L1<L3/2 L2≦̸L3/3 where L1 is a length of each groove, L2 is a length of a groove non-form rectangular region in the extending direction of the ridge, the groove non-form rectangular region being sandwiched by the grooves from the extending direction of the ridge, and L3 is a resonator length.
|
