Patent ID: 8472492

Claim:
A surface emitting laser element, comprising: a substrate made of GaAs; a lower multilayer film reflecting mirror formed on the substrate and formed of a periodic structure of a low-refractive-index layer made of Al x Ga 1-x As, where 0.8≦x≦1, and a high-refractive-index layer formed of Al y Ga 1-y As, where 0≦y≦x, at least one of the low-refractive-index layer and the high-refractive-index layer being of n-type; an upper multilayer film reflecting mirror provided above the lower multilayer film reflecting mirror, and formed of a periodic structure of a low-refractive-index layer and a high-refractive-index layer; an active layer provided between the lower multilayer film reflecting mirror and the upper multilayer film reflecting mirror; and a lower electrode provided at least between the lower multilayer film reflecting mirror and the active layer, and configured to inject an electric current into the active layer, wherein the lower multilayer film reflecting mirror is added with an n-type dopant, and a warp of the substrate is equal to or more than a warp of δ in μm defined by equation (1) below, where x ave denotes an average Al composition in the lower multilayer film reflecting mirror, n ave in cm −3 denotes an average addition concentration of the n-type dopant, d in μm denotes a thickness of the substrate, D in inches denotes a length of a longest one of lines each extending from one of vertexes of the substrate through a center of gravity of the substrate to an edge of the substrate: δ = 1.71 × 10 6 ⁢ λ × [ ( 1.39 × 10 - 3 ) ⁢ x ave - ( 1.28 × 10 - 23 ) ⁢ n ave ] × ( D d ) 2 . ( 1 )