High-power 390-nm laser source based on efficient frequency doubling of a tapered diode laser in an external resonant cavity.

We frequency doubled the single-frequency beam from an external-cavity tapered laser diode operating at 780 nm in a resonant cavity containing a beta -barium borate crystal to generate an output at 390 nm with high efficiency. Output powers as great as 233 mW were obtained, corresponding to an efficiency of 65%/W . The resonant-cavity design was a low-loss three-mirror configuration that provided compensation for astigmatism and coma. The laser diode frequency was locked to the doubling-cavity resonance by use of the Hänsch-Couillaud discrimination technique.

Transverse-Flow Quasi-cw HF Chemical Laser: Design and Preliminary Performance.

A small transverse-flow HF chemical laser has been constructed using a large volume microwave plasma generator for the production of F atoms. The F atoms react with hydrogen to form the lasing HF molecules. The active medium is about 5 cm long, and the maximum average laser power was found to be 560mW for all lines. Three laser lines with wavelengths 2.61 microm, 2.64 microm, and 2.73 microm were observed. The time-varying laser transition profile closely resembles the density profile of the excited fluorine atoms in the plasma. Both profiles are greatly affected by changes in flow conditions.