Abstract: A total of n light receiving surface finger electrodes are arranged on a light receiving surface. A total of (n?1)×m1/m2+1 second collecting electrodes are arranged on a back surface. On a plane of projection parallel, m2 light receiving surface finger electrodes and ml back surface finger electrodes are included an interval between a first position and a second position. On the plane of projection, the auxiliary wiring is provided at a third position at which only the light receiving surface finger electrode is present. A length of the auxiliary wiring is smaller than a length of the back surface finger electrode.

Abstract: A semiconductor laser diode capable of further improving temperature characteristics while sufficiently preventing a laser beam emission end surface portion from thermal destruction through a window structure is obtained. This semiconductor laser diode comprises an active layer having a window structure on a laser beam emission end surface portion and a p-type layer, formed on the surface of the active layer, containing Mg and Zn as impurities. The impurity concentration of Zn contained in the p-type layer is larger than the impurity concentration of Mg contained in the p-type layer.

Abstract: A semiconductor laser diode capable of further improving temperature characteristics while sufficiently preventing a laser beam emission end surface portion from thermal destruction through a window structure is obtained. This semiconductor laser diode comprises an active layer having a window structure on a laser beam emission end surface portion and a p-type layer, formed on the surface of the active layer, containing Mg and Zn as impurities. The impurity concentration of Zn contained in the p-type layer is larger than the impurity concentration of Mg contained in the p-type layer.