title: Phase-coherent link from optical to microwave frequencies by means of the broadband continuum from a 1-GHz Ti:sapphire femtosecondoscillator.
abstract: An optical clockwork is created with a compact 1-GHz repetition-rate laser and three nonlinear crystals. The broadband continuum output of the laser covers sufficient bandwidth to provide direct access to its carrier-envelope offset frequency without the use of a microstructure fiber. We phase lock the femtosecond comb to a Ca optical standard and monitor the stability of the repetition rate, f(r) , at 1 GHz. We demonstrate that the short-term stability of the microwave output of the optical clock is at least as good as that of a high-performance hydrogen maser.
authors.forename: T M
authors.initials: TM
authors.lastname: Ramond
authors.forename: S A
authors.initials: SA
authors.lastname: Diddams
authors.forename: L
authors.initials: L
authors.lastname: Hollberg
authors.forename: A
authors.initials: A
authors.lastname: Bartels