Semiconductor laser element

A semiconductor laser element comprising:

• a substrate;
• a first semiconductor layer disposed above the substrate;
• a light emission layer disposed above the first semiconductor layer;
• a second semiconductor layer disposed above the light emission layer;
• and
• a groove part formed at least at the substrate and the first semiconductor layer, wherein
• the second semiconductor layer has a ridge part for guiding laser light generated in the light emission layer,
• a width of the ridge part cyclically changes in accordance with a position in a waveguiding direction of the ridge part,
• an angle between a side face of the ridge part and the waveguiding direction is larger than a limit angle defined by an effective refractive index on each of an inner side of the ridge part and an outer side of the ridge part, and
• the groove part is disposed on the outer side of the side face at least where the width of the ridge part is small.