Semiconductor laser element

A semiconductor laser element comprising:

• a first semiconductor layer that is a III-V group compound semiconductor layer containing at least As as a group V element;
• a second semiconductor layer of a first conductivity type side located above the first semiconductor layer, the second semiconductor layer being a III-V compound semiconductor layer containing at least P as a group V element;
• a third semiconductor layer of a second conductivity type side located above the second semiconductor layer;
• an active layer disposed between the second semiconductor layer and the third semiconductor layer;
• a window structure formed across the third semiconductor layer, the active layer, the second semiconductor layer, and the first semiconductor layer;
• a defect layer comprising a defect, the defect layer being located in a region in which the window structure is formed and between the first semiconductor layer and the second semiconductor layer, the defect layer containing a group III element of the first semiconductor layer and a group III element of the second semiconductor layer;
• and
• an end surface emitting a laser light, the end surface comprising a surface of the defect layer;
• wherein:
• the semiconductor laser element satisfies Equation (1):
• y≥2.31×10−5x2−5.37×10−2x+4.44 (1)
• where x is a divergence angle (°) of a far-field pattern of the laser light in the direction from the first semiconductor layer to the active layer, and y is a thickness (μm) of the second semiconductor layer.