Patent attributes
A semiconductor laser device includes a chip obtained from a substrate and a semiconductor multi-layer formed on the substrate. The semiconductor multi-layer is formed from a plurality of semiconductor layers of a semiconductor material having a hexagonal structure, and includes a stripe-shaped wave guide portion. The chip includes two chip end facets that extend in a direction crossing an extending direction of the wave guide portion. Each of regions on both sides of the wave guide portion in at least one of the chip end facets has a notch portion formed by notching a part of the chip, and the notch portion exposes a first wall surface connecting to the chip end facet and a second wall surface connecting to the chip side facet. An angle between an extending direction of the first wall surface in at least one of the two notch portions and an extending direction of the cleavage facet is in a range of about 10 degrees to about 40 degrees.