A method for independent and continuous tuning of $N$ lasers phase-locked to the same frequency comb

TL;DR

This paper introduces a novel method for independently and continuously tuning multiple lasers phase-locked to a single optical frequency comb, allowing precise control over each laser's frequency.

Contribution

The method employs a double pass AOM setup for each laser, enabling independent frequency positioning while maintaining lock to the OFC, with demonstrated high tuning precision and rate.

Findings

Achieved arbitrary frequency tuning precision.

Demonstrated a tuning rate of 200 MHz/s.

Readout precision at the 1 kHz level.

Abstract

We present a method of phase-locking any number of continuous-wave lasers to an optical frequency comb (OFC) that enables independent frequency positioning and control of each laser while still maintaining lock to the OFC. The scheme employs an acousto-optic modulator (AOM) in a double pass configuration added to each laser before its light is compared by optical heterodyne with the comb. The only requirement is that the tuning bandwidth of the double pass AOM setup be larger than half the OFC repetition rate. We demonstrate this scheme and achieve an arbitrary frequency tuning precision, a tuning rate of 200~MHz/s and a readout precision at the 1~kHz level.