Abstract: A semiconductor laser of present invention is constructed by an aluminum oxide (Al2O3) film on an end surface opposed to a beam emission surface of the semiconductor laser, a silicon nitride (SiNx, or Si3N4) film on the aluminum oxide film, and a silicon oxide (SiO2) film on the silicon nitride film. These films are made successively by a method of Electron Cyclotron Resonance (ECR) sputtering.

Abstract: Disclosed is a semiconductor laser capable of preventing diffusion of a p-type dopant to an active layer while performing sufficient carrier blocking, even when Zn is used as a p-type dopant, and obtaining high emission efficiency and high output by minimizing light absorption in a p-type cladding layer. This semiconductor laser includes an active layer and p-type cladding layer on an n-type semiconductor substrate. The concentration distribution of a p-type dopant from the active layer to the p-type cladding layer has a maximum value at a distance of 50 to 250 nm from the end of the active layer.

Abstract: A semiconductor laser pumped solid state laser includes a solid laser medium, a semiconductor laser which radiates a pumping laser beam for pumping the solid laser medium, and a light entrance optical system which converges the pumping laser beam in the solid laser medium. The semiconductor laser is disposed with its beam radiating axis inclined to the optical axis of the light entrance optical system so that the pumping laser beam travelling from the semiconductor laser to the solid laser medium and a laser beam reflected at the pumping light inlet side end face of the solid laser medium travel different optical paths. A light-shielding plate which intercepts the laser beam reflected at the pumping light inlet side end face of the solid laser medium is provided between the semiconductor laser and the solid laser medium.