Generation of tunable continuous-wave ultraviolet radiation from 257 to 320 nm

The generation of tunable cw radiation by sum-frequency mixing the output of a Rhodamine 6G laser and selected output lines of an argon-ion laser in an angle-tuned KDP crystal has been investigated. This technique, coupled with second-harmonic generation of the Rhodamine 6G laser, provides a simple source of cw ultraviolet radiation, continuously tunable from 257 to 320 nm, with a maximum output power in excess of 250, mu W and a bandwidth of less than 0.03 nm.