Surface-emitting unstable-resonator lasers with integrated diffractive beam-forming elements

Grating-coupled surface-emitting semiconductor lasers have been integrated with focusing and spot array generating diffractive beam-forming elements. The lasers have an unstable resonator producing a 160-μm-wide single spatial mode. The area of the outcoupler element is 160 μm×240 μm. For an outcoupler focusing at 500 μm above the surface the spot size is 9 μm×17 μm The spot size is primarily limited by aberrations in the wavefront of the guided mode.