# Fast, precise, and widely tunable frequency control of an optical parametric oscillator referenced to a frequency comb

## TL;DR

This paper presents a rapid, precise, and widely tunable frequency control method for an optical parametric oscillator using an optical frequency comb as a reference, enabling fast frequency ramps and stable locking.

## Contribution

It introduces a novel control technique combining fast frequency ramps with precise stabilization, applicable to commercial OPOs, achieving over 60 GHz tuning and sub-MHz stability.

## Key findings

- Tuning over 60 GHz with 3 GHz/ms ramping speed.
- 15 GHz frequency ramps completed in less than 10 ms.
- Achieved sub-MHz stabilization accuracy.

## Abstract

Optical frequency combs (OFC) provide a convenient reference for the frequency stabilization of continuous-wave lasers. We demonstrate a frequency control method relying on tracking over a wide range and stabilizing the beat note between the laser and the OFC. The approach combines fast frequency ramps on a millisecond timescale in the entire mode-hop free tuning range of the laser and precise stabilization to single frequencies. We apply it to a commercially available optical parametric oscillator (OPO) and demonstrate tuning over more than 60 GHz with a ramping speed up to 3 GHz/ms. Frequency ramps spanning 15 GHz are performed in less than 10 ms, with the OPO instantly relocked to the OFC after the ramp at any desired frequency. The developed control hardware and software is able to stabilize the OPO to sub-MHz precision and to perform sequences of fast frequency ramps automatically.