Oberflächenemittierender Laser mit vertikalem Resonator und lateraler Ladungsträgerinjektion

A lateral injection VCSEL comprises upper and lower mirrors (12,14) forming a cavity resonator, an active region (16) disposed in the resonator, high conductivity upper and lower contact layers (18.1,22) located on opposite sides of the active region, upper and lower electrodes (18.4,26) disposed on the upper and lower contact layers, respectively, and on laterally opposite sides of the upper mirror, and a current guide structure (18) including an apertured high resistivity layer (18.3) for constraining current to flow in a relatively narrow channel through the active region, characterized in that a portion (22.1) of the lower contact layer (22) that extends under the top electrode has relatively high resistivity. This feature of the invention serves two purposes. First, it suppresses current flow in parallel paths and, therefore, tends to make the current density distribution in the aperture more favorable for the fundamental mode. Second, it reduces parasitic capacitance.