Nitride semiconductor laser element

A nitride semiconductor laser element comprising:

• an n-type semiconductor layer comprising an n-side optical guide layer;
• a p-type semiconductor layer;
• and
• an active layer disposed between the n-type semiconductor layer and the p-type semiconductor layer, the active layer comprising two or more well layers, and at least one barrier layer disposed between the well layers,
• wherein the p-type semiconductor layer comprises an electron barrier layer having band gap energy higher than that of all barrier layers comprised in the active layer,
• wherein a p-side optical guide layer is disposed between a final well layer and the electron barrier layer, the final well layer being a well layer nearest to the p-type semiconductor layer of the two or more well layers,
• wherein the p-side optical guide layer comprises a composition graded layer of AlxInyGa1-x-yN (0≦x<1, 0≦y<1, 0≦x+y<1) having band gap energy increasing approximately linearly from a side of the final well layer to a side of the electron barrier layer, and
• wherein a region of the composition graded layer on a side of the final well layer has a lower band gap energy than that of the barrier layer.