Direct measurement of pump intensity distributions in an optically pumped vertical-cavity surface-emitting laser

In conclusion, we have demonstrated the direct mapping of the internal pump intensity distribution of an optically pumped AlGaAs QW VCSEL laser structure. The technique is made possible by the combination of distributed quantum wells through the mirror stacks and near-field scanning optical microscopy. This technique is a valuable tool for directly evaluating the spatial distribution of the pump field as a function of wavelength. These results will be extended in future work to optimise devices which tailor the thickness of the mirror layers to achieve a desired spectral and spatial function of pump field overlap with the active region