Broadly tunable mid-infrared femtosecond pulses directly generated by an optical parametric amplifier

作者：Andrea Villa, Aaron M. Ross, Riccardo Gotti, Marco Lamperti, Francesco Scotognella, Giulio Cerullo, Marco Marangoni · 发表于：OSA Continuum · 年份：2021 · DOI：10.1364/osac.439298 · 被引用次数：27 · 研究领域：Laser-Matter Interactions and Applications、Advanced Fiber Laser Technologies、Spectroscopy Techniques in Biomedical and Chemical Research

We introduce an optical parametric amplifier, pumped by an amplified femtosecond Yb:KGW laser, which directly generates broadly tunable mid-infrared (MIR) pulses, covering the whole vibrational spectrum from 3 to 10 µm. The avoidance of the traditional difference-frequency generation stage to access the MIR range simplifies the setup while enabling high conversion efficiencies. The two-stage design employs in the second stage either periodically poled lithium niobate, optimized for the CH/OH stretching region (3-5 µm) or LiGaS 2 , which allows extending the tunability to the fingerprint region (up to 10 µm). We anticipate applications of this versatile source to ultrafast vibrational spectroscopy and infrared microscopy.