Three-Wave Mixing between Continuous-Wave and Ultrafast Lasers

TL;DR

This paper introduces a simple method for wavelength conversion in ultrafast laser systems using sum-frequency generation between a continuous-wave Nd:YAG laser and a Yb:fiber femtosecond comb, offering a cost-effective alternative to complex traditional systems.

Contribution

It demonstrates a novel, easy-to-implement approach for tunable frequency comb generation via sum-frequency mixing with continuous-wave lasers, supported by simulations for system design.

Findings

Sum-frequency generation produces a pulsed comb with the same repetition rate as the Yb:fiber source.

SNLO software effectively simulates and benchmarks the wavelength conversion process.

The method enables tunability in spectral regions that are difficult to access with existing systems.

Abstract

Ultrafast optical frequency combs allow for both high spectral and temporal resolution in molecular spectroscopy and have become a powerful tool in many areas of chemistry and physics. Ultrafast lasers and frequency combs generated from ultrafast mode-locked lasers often need to be converted to other wavelengths. Commonly used wavelength conversions are optical parametric oscillators, which require an external optical cavity, and supercontinuum generation combined with optical parametric amplifiers. Whether commercial or home-built, these systems are complex and costly. Here we propose an alternative, simple, and easy-to-implement approach to tunable frequency comb ultrafast lasers enabled by new continuous-wave laser technology. Sum-frequency generation between a Nd:YAG continuous-wave laser and a Yb:fiber femtosecond frequency comb in a beta-barium borate (BBO) crystal is explored. The resulting sum-frequency beam is a pulsed frequency comb with the same repetition rate as the Yb:fiber source. SNLO simulation software was used to simulate the results and provide benchmarks for designing future system to achieve wavelength conversion and tunability in difficult spectral regions.