Ultrafast Structured Light through Nonlinear Frequency Generation in an Optical Enhancement Cavity

TL;DR

This paper introduces a novel method for generating ultrafast, structured light across a broad wavelength range using nonlinear frequency generation in an optical enhancement cavity, overcoming limitations of traditional spatial light modulators.

Contribution

The authors demonstrate a new technique that employs optical cavities and nonlinear crystals to produce shaped ultrafast light at any wavelength, with high power and flexibility.

Findings

Able to generate structured light from UV to IR wavelengths

Compatible with ultrafast pulses and high optical powers

Uses cavity mode matching and nonlinear frequency conversion

Abstract

The generation of shaped laser beams, or structured light, is of interest in a wide range of fields, from microscopy to fundamental physics. There are several ways to make shaped beams, most commonly using spatial light modulators comprised of pixels of liquid crystals. These methods have limitations on the wavelength, pulse duration, and average power that can be used. Here we present a method to generate shaped light that can be used at any wavelength from the UV to IR, on ultrafast pulses, and a large range of optical powers. By exploiting the frequency difference between higher order modes, a result of the Gouy phase, and cavity mode matching, we can selectively couple into a variety of pure and composite higher order modes. Optical cavities are used as a spatial filter and then combined with sum frequency generation in a nonlinear crystal as the output coupler to the cavity to create ultrafast, frequency comb structured light.