Abstract

Several techniques have recently been examined for fabricating unstable resonator diode lasers, namely reactive-ion-etching (RIE) and ion-beam-milling to create curved cavity mirrors, epitaxial regrowth to effect divergent lenses within the gain stripe, and cavity micro-heating to thermally induce index change. Of these, the last three approaches have demonstrated nearly diffraction-limited output at high powers, but to our knowledge, such ideal characteristics have not been realized with the highly manufacturable RIE process. We have fabricated wide-stripe unstable resonators using RIE and have measured M² beam quality values nearly equivalent to those obtainable from narrow-stripe diode lasers.

© 1994 Optical Society of America