Analysis of spatial emission structures in vertical-cavity surface-emitting lasers with feedback from a volume Bragg grating

We investigate the spatial and spectral properties of broad-area vertical-cavity surface-emitting lasers with frequency-selective feedback by a volume Bragg grating. We demonstrate wavelength locking similar to the case of edge emitters but the spatial mode selection is different from the latter. On-axis spatial solitons obtained at threshold give way to off-axis extended lasing states beyond threshold. The investigations focus on a self-imaging external cavity. We analyze how deviations from the self-imaging condition affect the pattern formation and a certain robustness of the phenomena is demonstrated.