O. de Vries,
T. Saule,
M. Plötner,
F. Lücking,
T. Eidam,
A. Hoffmann,
A. Klenke,
S. Hädrich,
J. Limpert,
S. Holzberger,
T. Schreiber,
R. Eberhardt,
I. Pupeza,
and A. Tünnermann

Opt. Express,

**Acousto-optic pulse picking scheme with carrier-frequency-to-pulse-repetition-rate synchronization**Opt. Express,

**23**:19586 (July 2015)## Abstract:

We introduce and experimentally validate a pulse picking technique based on a travelling-wave-type acousto-optic modulator (AOM) having the AOM carrier frequency synchronized to the repetition rate of the original pulse train. As a consequence, the phase noise characteristic of the original pulse train is largely preserved, rendering this technique suitable for applications requiring carrier-envelope phase stabilization. In a proof-of-principle experiment, the 1030-nm spectral part of an 74-MHz, carrier-envelope phase stable Ti:sapphire oscillator is amplified and reduced in pulse repetition frequency by a factor of two, maintaining an unprecedentedly low carrier-envelope phase noise spectral density of below 68 mrad. Furthermore, a comparative analysis reveals that the pulse-picking-induced additional amplitude noise is minimized, when the AOM is operated under synchronicity. The proposed scheme is particularly suitable when the down-picked repetition rate is still in the multi-MHz-range, where Pockels cells cannot be applied due to piezoelectric ringing.