Lateral injection VCSEL

A VCSEL comprises a pair of multi-layered mirrors forming an optical cavity resonator having its axis perpendicular to the layers of the mirrors, an active region disposed within the resonator, and a current guide for directing pumping current through an aperture to generate stimulated emission of radiation which propagates along the resonator axis. A portion of the radiation forms an output signal which emerges through at least one of the mirrors. The current guide includes a lateral injection structure disposed between one of the mirrors and the current aperture. The lateral injection structure comprises at least one relatively thin, highly doped semiconductor layer, each of the highly doped layer(s) being located at a node of the standing wave of the intracavity radiation, at least one lower doped semiconductor layer disposed adjacent each of the highly doped layers (e.g., one lower doped layer sandwiched between a pair of highly doped layers), and an etch stop layer disposed between the one mirror and the uppermost highly doped layer.