title: Vacuum ultraviolet frequency combs generated by a femtosecond enhancement cavity in the visible.
abstract: We present the first (to our best knowledge) femtosecond enhancement cavity in the visible wavelength range for ultraviolet frequency comb generation. The cavity is seeded at 518 nm by a frequency-doubled Yb fiber laser and operates at a peak intensity of 1.2×10(13) W/cm(2). High harmonics of up to the ninth order (~57 nm) are generated in an intracavity xenon gas jet. Intracavity high harmonic powers of several milliwatts for the third harmonic order and microwatts for the fifth harmonic order prove the potential of the "green cavity" as an efficient ultraviolet frequency comb source for future spectroscopic experiments. A limiting degradation effect of the cavity mirrors is avoided by operating at a constant oxygen background pressure.
authors.affiliation: Max-Planck-Institut für Quantenoptik, Garching, Germany. Birgitta.Bernhardt@mpq.mpg.de
authors.forename: Birgitta
authors.initials: B
authors.lastname: Bernhardt
authors.forename: Akira
authors.initials: A
authors.lastname: Ozawa
authors.forename: Andreas
authors.initials: A
authors.lastname: Vernaleken
authors.forename: Ioachim
authors.initials: I
authors.lastname: Pupeza
authors.forename: Jan
authors.initials: J
authors.lastname: Kaster
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Ronald
authors.initials: R
authors.lastname: Holzwarth
authors.forename: Ernst
authors.initials: E
authors.lastname: Fill
authors.forename: Ferenc
authors.initials: F
authors.lastname: Krausz
authors.forename: Theodor W
authors.initials: TW
authors.lastname: Hänsch
authors.forename: Thomas
authors.initials: T
authors.lastname: Udem