Internal focus 980 nm unstable resonator laser diodes

Unstable laser resonators can make use of a large mode volume while retaining a single mode for the resonator thereby overcoming limitations associated with narrow aperture lasers. Our half-symmetric geometry is shown and contains an etched circular mirror and a tapered metal contact pattern to follow the desired mode. The output is taken from the cleaved facet and results in an astigmatism between the lateral and transverse beam propagation. The devices are fabricated from epitaxial material with a single quantum well.