Megawatt Tunable Second Harmonic and Sum Frequency Generation at 280 nm from a Dye Laser

Abstract
The second harmonic frequency of a high‐power interferometrically narrowed and tuned rhodamine 6G dye laser has been generated in an ADP crystal with 10% efficiency. Twenty‐millijoule‐megawatt pulses, continuously wavelength tunable from 280 to 290 nm, have been obtained with a bandwidth of 0.2 nm. Ultraviolet sum frequencies have also been generated with similar efficiency.