Tunable,continuous-wave,ultra-violet radiation around 300 nm by frequency-doubling a rhodamine 6G dye laser

By frequency doubling a cw Rhodamine 6G dye laser using an ADP crystal placed in the laser cavity, in excess of 30 mW of cw uv radiation has been generated. The radiation is tunable over the range 285–315 nm. The ADP crystal is cut with Brewster angle ends, and is located at the focus of cavity compensated for coma and astigmatism. Conversion efficiency is shown to be limited by the onset of thermally induced phase mismatching. Peak uv power can be increased to 85 mW by chopping the radiation from the pumping laser.