Abstract: A nitride semiconductor laser device comprises, on a principle face of a nitride semiconductor substrate: a nitride semiconductor layer having a first conductivity type; an active layer comprising indium, and a nitride semiconductor layer having a second conductivity type that is different from said first conductivity type, and on the surface of which is formed a stripe ridge; said principal face of said nitride semiconductor substrate having an off angle a (?a) with respect to a reference crystal plane, in at least a direction substantially parallel to said stripe ridge.

Abstract: A nitride semiconductor laser element comprises; a nitride semiconductor layer that includes a first nitride semiconductor layer, an active layer, and a second nitride semiconductor layer, and that has a cavity with end faces, and a protective film formed on at least one end face of the cavity, wherein the protective film is formed of a first film with a crystal structure that has the same axial orientation as that of the nitride semiconductor layer constituting the end face of the cavity, and a second film with a crystal structure that has a different axial orientation from that of the first film, in this order from the side of the end face.

Abstract: A nitride semiconductor laser element, has: a nitride semiconductor layer comprising a first nitride semiconductor layer, an active layer, and a second nitride semiconductor layer laminated in that order; and resonator end faces formed mutually opposing at the end of said nitride semiconductor layers, wherein an impurity is contained in at least an optical output region of the resonator end faces, with the concentration of said impurity having a concentration distribution that is asymmetric in reference to a peak position, in the lamination direction of the nitride semiconductor layers, and said optical output region has a wider bandgap than other regions in the active layer or said optical output region has a higher impurity concentration than other regions in the active layer.

Abstract: A nitride semiconductor laser device comprises, on a principle face of a nitride semiconductor substrate: a nitride semiconductor layer having a first conductivity type; an active layer comprising indium, and a nitride semiconductor layer having a second conductivity type that is different from said first conductivity type, and on the surface of which is formed a stripe ridge; said principal face of said nitride semiconductor substrate having an off angle a (?a) with respect to a reference crystal plane, in at least a direction substantially parallel to said stripe ridge.