High-bandwidth transfer of phase stability through a fiber frequency comb

TL;DR

This paper demonstrates a high-bandwidth phase transfer technique using a fiber frequency comb, enabling high-fidelity quantum control of ions without pre-stabilizing the slave laser.

Contribution

It introduces a transfer-oscillator feedforward scheme that suppresses comb noise over 1.8 MHz bandwidth, improving phase stability for quantum applications.

Findings

Achieved 99% fidelity in ion manipulation at microsecond timescales

Demonstrated phase locking over 1.8 MHz bandwidth

Enabled high-fidelity quantum logic without pre-stabilization

Abstract

We demonstrate phase locking of a 729 nm diode laser to a 1542 nm master laser via an erbium-doped-fiber frequency comb, using a transfer-oscillator feedforward scheme which suppresses the effect of comb noise in an unprecedented 1.8 MHz bandwidth. We illustrate its performance by carrying out coherent manipulations of a trapped calcium ion with 99 % fidelity even at few-microsecond timescales. We thus demonstrate that transfer-oscillator locking can provide sufficient phase stability for high-fidelity quantum logic manipulation even without pre-stabilization of the slave diode laser.