Patent ID: 8494022

Claim:
A surface emitting laser, comprising: a substrate; a lower multilayer film reflection mirror formed on the substrate and comprising a periodic structure of a high refractive index layer and a low refractive index layer; a first conductivity type contact layer formed on the lower multilayer film reflection mirror; a first conductivity type cladding layer formed on the first conductivity type contact layer; an active layer formed on the first conductivity type cladding layer; a second conductivity type cladding layer formed on the active layer; a current confinement layer formed on the second conductivity type cladding layer and including a current injection portion made of a material including aluminum and a current confinement portion made of aluminum oxide formed by a selective thermal oxidation process; a second conductivity type contact layer formed on the current confinement layer; an upper multilayer film reflection mirror formed on the second conductivity type contact layer and comprising a periodic structure of a high refractive index layer and a low refractive index layer; a second conductivity type side electrode formed on the second conductivity type contact layer; and a first conductivity type side electrode formed on the first conductivity type contact layer, wherein layers from immediately above the current confinement layer to the second conductivity type contact layer comprise a composition in which bandgap energy is reduced towards the second conductivity type contact layer in a stacking direction, layers from immediately below the current confinement layer to the first conductivity type contact layer comprise a composition in which bandgap energy is reduced towards the first conductivity type contact layer in the stacking direction, while bypassing a quantum well layer or a quantum dot of the active layer, the second conductivity type cladding layer includes a material for reducing mobility of a carrier, and at least one of (i) the bandgap energy of the layers from immediately above the current confinement layer to the second conductivity type contact layer and (ii) the bandgap energy of the layers from immediately below the current confinement layer to the first conductivity type contact layer is reduced in a stepwise manner.