Unstable resonator semiconductor lasers. Part 2: Experiment

We review the technology involved in the fabrication of semiconductor lasers with non-planar mirrors. The symmetric unstable resonator semiconductor laser, in a planar (gain guided) configuration is shown to effectively suppress filamentation, and to emit a laterally coherent output up to approximately 350 mW. We show how the geometry of this laser can be changed slightly to produce different devices with improved output characteristics. As in the case of macroscopic resonators, the laser cavity can be designed in such a way that the output beam is optimised to certain specific applications.