Multi-watt long-wavelength infrared femtosecond lasers and resonant enamel ablation

TL;DR

This paper reports the development of high-power broadband tunable LWIR femtosecond lasers at 7-14 μm, demonstrating efficient resonant enamel ablation at 9.5 μm with potential for safer surgical applications.

Contribution

It introduces a new record in LWIR femtosecond laser power using LiGaS2 and BaGa4S7, and demonstrates resonant tissue ablation at lower intensities than traditional lasers.

Findings

Record output power of 2.4 W at 7.5 μm and 1.5 W at 9.5 μm.

Efficient resonant enamel ablation at 9.5 μm with lower laser intensity.

Potential for more precise and biosafe surgical procedures.

Abstract

High-power broadband tunable long-wavelength infrared (LWIR) femtosecond lasers operating at fingerprint wavelengths of 7-14 {\mu}m hold significant promise across a range of applications, including molecular hyperspectral imaging, strong-field light-matter interaction, and resonant tissue ablation. Here we present 6-12 {\mu}m broadband tunable parametric amplifier based on LiGaS2 or BaGa4S7, generating new record output power of 2.4 W at 7.5 {\mu}m, and 1.5 W at 9.5 {\mu}m, pumped by a simple and effective thin-square-rod Yb:YAG amplifier producing 110 W 274 fs output pulses. As a proof of concept, we showcase efficient resonant ablation and microstructure fabrication on enamel at the hydroxyapatite resonant wavelength of 9.5 {\mu}m, with a laser intensity two orders-of-magnitude lower than that required by non-resonant femtosecond lasers, which could foster more precision surgical applications with superior biosafety.