Vertical cavity surface emitting semiconductor laser device

The vertical cavity surface emitting semiconductor laser device for emitting light vertically to an InP substrate comprising an active layer that generates light onto the InP substrate and a cavity-structure in which the upper and lower sides of the active layer are sandwiched by first and second reflectors in order to obtain a lasing light from light generated from the active layer,

• wherein the first reflector laminated on the InP substrate is comprised of first semiconductor layers, the active layer is laminated above the first reflector, and the second reflector laminated above the active layer is comprised of second semiconductor layers or first dielectric layers,
• wherein a partial region of the first semiconductor layers is doped with impurities as to be a first conductivity type so that current can be injected from the first semiconductor layers to the active layer, and
• the first semiconductor layers comprise a plurality of pairs of a multi-quantum-wells layer and an InP layer, wherein the plurality of pairs are laminated alternatively and the multi-quantum-wells layer is comprised of InGaAlAs-wells and InGaAlAs-barriers, wherein a doping concentration of the InGaAlAs-barriers is higher than a doping concentration of the InGaAlAs-wells of the multi-quantum-wells layer within the first semiconductor layers in the first reflector.