Vertical-cavity surface-emitting semiconductor laser

A vertical-cavity surface-emitting semiconductor laser comprising:

• a p-GaAs substrate;
• a first lower DBR mirror having a plurality of p-AlyGa1−yAs/AlzGa1−zAs(0<y<z) layers provided on said substrate;
• a semiconductor buried structure provided over said first lower DBR mirror and having an optical resonator region with a GaAs/AlxGa1−xAs active layer, and a AlwGa1−wAs (0<x<w) or InGaP current confinement layer peripherally surrounding the optical resonator region;
• and
• a first upper DBR structure portion having a plurality of n-AlyGa1−yAs/AlzGa1−zAs (0<y<z) layers provided over said optical resonator region and surrounded by said current confinement layer;
• and,
• wherein said optical resonator region includes said active layer sandwiched between a pair of AlwGa1−wAs spacer layers, a p-AlyGa1−yAs/AluGa1−uAs (0<y<u<z) second lower DBR mirror arranged under one of said spacer layers, a n-AlyGa1−yAs/AluGa1−uAs (0<y<u<z)second upper DBR mirror arranged on the other of the spacer layers;
• and, each of said layers and said upper and lower DBR mirrors constituting said optical resonator region has an effective refractive index higher than the effective refractive index of said current confinement layer.