title: A deep-UV optical frequency comb at 205 nm.
abstract: By frequency quadrupling a picosecond pulse train from a Ti:sapphire laser at 820 nm we generate a frequency comb at 205 nm with nearly bandwidth-limited pulses. The nonlinear frequency conversion is accomplished by two successive frequency doubling stages that take place in resonant cavities that are matched to the pulse repetition rate of 82 MHz. This allows for an overall efficiency of 4.5 % and produces an output power of up to 70 mW for a few minutes and 25 mW with continuous operation for hours. Such a deep UV frequency comb may be employed for direct frequency comb spectroscopy in cases where it is less efficient to convert to these short wavelengths with continuous wave lasers.
authors.affiliation: Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany. elisabeth.peters@mpq.mpg.de
authors.forename: E
authors.initials: E
authors.lastname: Peters
authors.forename: S A
authors.initials: SA
authors.lastname: Diddams
authors.forename: P
authors.initials: P
authors.lastname: Fendel
authors.forename: S
authors.initials: S
authors.lastname: Reinhardt
authors.forename: T W
authors.initials: TW
authors.lastname: Hänsch
authors.forename: Th
authors.initials: T
authors.lastname: Udem
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005374:Filtration / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation*; D014466:Ultraviolet Rays