Patent ID: 8624950

Claim:
A surface-emitting laser comprising: a substrate; a lower semiconductor multilayer film reflector disposed on the substrate; a resonator structure including an active layer and disposed on the lower semiconductor multilayer film reflector; an upper semiconductor multilayer film reflector disposed on the resonator structure, the upper semiconductor multilayer film reflector including a confinement structure in which a current passage region is surrounded by an oxidized portion of a selectively oxidized layer containing aluminum; and an upper electrode disposed on the upper semiconductor multilayer film reflector, the upper electrode defining an emission region, wherein the emission region includes a central portion and a peripheral portion, the peripheral portion being covered with a transparent dielectric film and having a reflectivity lower than a reflectivity of the central portion, wherein the selectively oxidized layer has a thickness in a range from 30 nm to 40 nm, and the temperature at which an oscillation threshold current is minimized is 60° C. or lower, wherein the peripheral portion of the emission region has optical anisotropy with respect to two directions perpendicular to each other, wherein the thickness of the dielectric film is λ/4n where λ is an oscillation wavelength and n is the refractive index of the dielectric film, wherein the peripheral portion includes a first peripheral portion and a second peripheral portion separated from each other by a straight line passing through the central portion disposed therebetween as viewed from a direction in which light is emitted from the laser, and wherein the central portion has a width in a range from 4.0 μm to 5.0 μm, and the straight line has a width in a range from 1.7 μm to 2.7 μm.