Spatial and spectral mode filtration in phase-locked array of injection lasers with volume Bragg grating

High-power edge-emitting lasers with low divergence of the output beam are highly desired for a number of applications. In order to obtain high optical power one needs to expand the emitting area of the laser which usually leads to multi-mode lasing with broad spectrum and poor beam quality. Here we present the study of using a volume Bragg grating (VBG) as a spatial and spectral mode filter for phase-locked arrays of edge-emitting lasers based on 1D photonic bandgap crystals. Emitters in the arrays are synchronized due to the expanded vertical waveguide, which results in the lasing of high order oscillating modes. One lobe of high order mode was used to create an external cavity with VBG. We studied far-fields, spectra and L-I curves of the external cavity lasers and demonstrated that 500 mW of the output optical power could be concentrated in one lobe with the divergence as low as 1° and spectral width of 0.6 nm.