Patent ID: 7738526

Claim:
A surface emitting semiconductor laser comprising: a substrate having a primary surface and a back surface, the primary surface having first to third areas, the first and second areas being contiguous to each other, and the third area surrounding the first and second areas; a first distributed Bragg reflector provided on the primary surface of the substrate; an active layer on the first distributed Bragg reflector, the active layer being provided on the first and second areas, and the active layer being provided on a boundary between the first and second areas, and; a first semiconductor spacer layer provided on the active layer; a second semiconductor spacer layer provided on the first semiconductor spacer layer, a conductivity type of the first semiconductor spacer layer being different from that of the second semiconductor spacer layer; a tunnel junction region on the first area, the tunnel junction region having a tunnel junction, the tunnel junction region being provided between the first semiconductor spacer layer and the second semiconductor spacer layer, the active layer, the first semiconductor spacer layer, the second semiconductor spacer layer, and the tunnel junction region constituting an optical cavity mesa, the optical cavity mesa including a low-resistance region and a high-resistance region, the low-resistance region being on the first area, the high-resistance region being on the second area, and the low-resistance region including the tunnel junction region; a second distributed Bragg reflector on the second semiconductor spacer layer and the first area, the first distributed Bragg reflector, the active layer, the tunnel junction region, and the second distributed Bragg reflector being arranged in a predetermined axis, and the predetermined axis passing across the primary surface and the back surface of the substrate: and a first electrode on the second semiconductor spacer layer, the first electrode being provided on the first and second areas and the boundary.