Wavelength beam combining of VECSELs using multiplexed volume Bragg gratings in a compound cavity

A method of wavelength beam combining to enhance the total output brightness of vertical external cavity surface emitting lasers (VECSELs) using multiplexed volume Bragg gratings (MVBGs) is presented. The MVBGs are designed to introduce wavelength-specific feedback for the 1020 nm near-infrared wavelength VECSELs to achieve both spectral stabilisation and beam combining effects. In conjunction with the compound cavity arrangement, a combined output of >6 W is achieved with >98% combining efficiency using two VECSELs. The beam combining scheme produces near-diffraction limited output with enhanced spectral density and wavelength-stabilised characteristics.