title: Doppler-free spectroscopy using a continuous-wave optical frequency synthesizer.
abstract: A continuous-wave (cw) optical frequency synthesizer is demonstrated by using a monolithic-type cw optical parametric oscillator (cw-OPO) and an optical frequency comb. The cw-OPO is phase locked to an optical frequency comb that is phase locked to an atomic clock. The output frequency of the cw-OPO is frequency shifted with an electro-optic modulator, which makes it possible to tune the frequency continuously over 10 GHz. Furthermore, Doppler-free spectroscopy is performed using the optical frequency synthesizer for a cesium D1 line at 895 nm. The observed linewidth of 5 MHz is the natural linewidth of cesium. The center frequency of the line is consistent with a previous report.
authors.affiliation: National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan. h.inaba@aist.go.jp
authors.forename: Hajime
authors.initials: H
authors.lastname: Inaba
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ikegami
authors.forename: Feng-Lei
authors.initials: FL
authors.lastname: Hong
authors.forename: Youichi
authors.initials: Y
authors.lastname: Bitou
authors.forename: Atsushi
authors.initials: A
authors.lastname: Onae
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Schibli
authors.forename: Kaoru
authors.initials: K
authors.lastname: Minoshima
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Matsumoto