Reactive-ion-etched diffraction-limited unstable resonator semiconductor lasers

We present characterization and analysis of wide-stripe unstable resonator semiconductor lasers with reactive-ion-etched facets. The mirror facets have RMS roughnesses of only 3-5 mm. Laser beam quality and brightness performance are measured in terms of resonator structure and fabrication parameters. Lateral M/sup 2/ values as low as 1.25 at five times threshold are found. This data is compared to that derived from a Huygen's integral-beam propagation method simulation which includes appropriate physical and process-induced aberrations, and good agreement is found.