Monolithic integration of vertical-cavity laserdiodes with refractive GaAsmicrolenses

Beam collimation and focusing, necessary for practical use of vertical-cavity laser diodes, is achieved by the monolithic integration of lasers with refractive microlenses etched on the back side of the GaAs substrate. For 7 µm diameter lasers, an original beam divergence of 6.5° was reduced to 1.9° and increased to 12.3° with lenses of focal lengths ~220 µm, and ~60 µm, respectively.