title: Generation of continuous-wave radiation near 243 nm by sum-frequency mixing in an external ring cavity.
abstract: We have generated up to 1 mW of single-mode cw ultraviolet radiation between 243 and 247 nm by mixing the outputs of an ultraviolet argon-ion laser at 363.8 nm and a red LD700 dye laser in ammonium dihydrogen phosphate. The dye-laser intensity within the crystal is enhanced by using an actively locked passive ring cavity. Wavelengths near 243.1 nm are of particular interest for the high-resolution two-photon spectroscopy of atomic hydrogen.
authors.forename: B
authors.initials: B
authors.lastname: Couillaud
authors.forename: L A
authors.initials: LA
authors.lastname: Bloomfield
authors.forename: T W
authors.initials: TW
authors.lastname: Hänsch