Nitride semiconductor laser device and optical device using the same

A nitride semiconductor laser device, comprising:

• n-type and p-type layers made of nitride semiconductor and formed on a substrate, and
• a light emitting layer provided between said n-type and p-type layers,
• said light emitting layer being formed of a well layer or a combination of well and barrier layers,
• at least the well layer among constituent layers of said light emitting layer being made of nitride semiconductor containing element X, N and Ga, wherein element X is at least one selected from the group consisting of As, P and Sb,
• in said nitride semiconductor containing said element X, N and Ga, element X having an atomic fraction smaller than that of said N, and
• a maximum width through which current is to be injected into said light emitting layer via said p-type layer being from 1.0 μm to 3.5 μm, and said nitride semiconductor laser device having a self oscillation characteristic.