Patent ID: 7693203

Claim:
A vertical cavity surface emitting laser (VCSEL) involving a multi-layer structure comprising different regions defined in one or more layers, the relations between the different regions being determined in a projection along a direction normal to the layers, the VCSEL comprising: a semiconductor material layer having an active region for generating light and for emitting the generated light, first and second at least substantially parallel mirrors forming a laser cavity comprising the active region, the laser cavity and the active region supporting at least one longitudinal electromagnetic mode for the generated light, a central light aperture (LA) region providing a long photon lifetime and overlapping with the active region, a mode-shaping (MS) region formed within or adjacent to the first and/or the second mirror and encircling the LA-region, the MS-region providing a shorter photon lifetime than the LA-region, a mode confinement (MC) region formed within or adjacent to the first and/or the second mirror and encircling the MS-region, and designed to provide lateral confinement of modes to the MS-region and the LA-region, wherein dimensions of the LA-region, the MS-region and the MC-region are selected to engineer an efficiency of laser action in each transverse electromagnetic mode of the cavity and the LA-region is an anti-guide with respect to the MS-region and the MS-region is designed to reduce/minimise lateral confinement of modes to the LA-region.