Patent ID: 7515621

Claim:
A nitride semiconductor laser element comprising a lower clad layer, a lower adjacent layer, a quantum well active layer, an upper adjacent layer, and an upper clad layer, arranged in this order, wherein said quantum well active layer includes a plurality of well layers formed of undoped InGaN, and an undoped barrier layer sandwiched between said well layers, said barrier layer includes a first layer formed of InGaN, a second layer formed of GaN, and a third layer formed of InGaN, an indium (In) composition ratio of said first layer and an indium (In) composition ratio of said third layer are each below half of an indium (In) composition ratio of said well layer; the lower adjacent layer is in contact with the well layer in a lowermost part of the quantum well active layer, the lower adjacent layer being undoped and being formed of GaN or InGaN; and the upper adjacent layer is in contact with well layer in an uppermost part of the quantum well active layer, the upper adjacent layer being undoped and being formed of GaN or InGaN.