We present an optically-stabilized Yb:KYW fs-laser frequency comb. We use an f-2f nonlinear interferometer to measure the carrier envelope offset frequency (f0) and the heterodyne beatnote between the comb and a stable CW laser at 1068 nm to detect fluctuations in the comb repetition rate (frep). Both of these degrees of freedom of the comb are then controlled using phase-locked loops. As a demonstration of the frequencystabilized comb, we generate low-phase-noise 10 GHz microwaves through detection of the pulse train on a high bandwidth photodiode. The Allan deviation of the resulting 10 GHz microwaves was measured to be <2.6 x 10-15 at 1 s by comparison to an independently-stabilized Ti:Sapphire frequency comb. This room-temperature, optically-based source of microwaves has close-to-carrier phase noise comparable to the very best cryogenic microwave oscillators.
Citation: Applied Physics B
Pub Type: Journals
Frequency comb, laser, microwaves, phase noise