Full phase stabilization of a Yb:fiber femtosecond frequency comb via high-bandwidth transducers

TL;DR

This paper demonstrates full phase stabilization of a Yb:fiber femtosecond frequency comb using high-bandwidth transducers, achieving low phase noise and robust locking to optical references for precision metrology.

Contribution

The authors introduce a method for stabilizing a Yb:fiber frequency comb with intra-cavity electro-optic and acousto-optic modulators, enabling high servo bandwidths and improved phase noise performance.

Findings

Achieved servo bandwidths of 580 kHz and 250 kHz for f_rep and f_ceo.

Maintained low phase errors of 0.21 rad and 0.47 rad when locked to an ultra-stable optical reference.

Successfully locked the comb to two optical references at 698 nm and 1064 nm.

Abstract

We present full phase stabilization of an amplified Yb:fiber femtosecond frequency comb using an intra-cavity electro-optic modulator and an acousto-optic modulator. These transducers provide high servo bandwidths of 580 kHz and 250 kHz for frep and fceo, producing a robust and low phase noise fiber frequency comb. The comb was self-referenced with an f - 2f interferometer and phase locked to an ultra-stable optical reference used for the JILA Sr optical clock at 698 nm, exhibiting 0.21 rad and 0.47 rad of integrated phase errors (over 1 mHz - 1 MHz) respectively. Alternatively, the comb was locked to two optical references at 698 nm and 1064 nm, obtaining 0.43 rad and 0.14 rad of integrated phase errors respectively.