Optical manipulation of current confinement in VCSELs with an external laser beam

We have devised an oxide- and regrowth-free approach for current confinement in vertical-cavity surface-emitting lasers (VCSELs) which uses the photons in the cavity to optically define a current path through the device. For this purpose, an optical switch, implemented as a phototransistor (PT), is epitaxially integrated into the cavity. The PT layers become locally conductive where the highest photon density is reached in the resonator and establish the current aperture. By introducing additional photons with an external laser beam into the resonator, we show here that this current aperture can be manipulated. We demonstrate the possibility of redefining the location of the current aperture and discuss the consequences on the light current characteristics of the devices.