Femtosecond long-wave-infrared generation in hydrogen-filled hollow-core fiber
This paper is chosen as Spotlight on Optics.
Generating femtosecond long-wave-infrared (LWIR) pulses is currently restricted to CO2 lasers and solid-state frequency converters, but waveguide-based Raman red shifting offers a promising alternative. In this study, we used a hydrogen-filled hollow-core fiber to generate LWIR pulses and found that a waveguide structure allows for tailored Raman gain. Using a two-pulse scheme with a two-color source, we achieved a numerical generation of clean 88-fs pulses at 12 μm with 41% total quantum efficiency. Our simulations also shed light on the nonlinear dynamics of the Raman gain, emphasizing the importance of a phonon amplifier for optimal performance.
In this work, especially its supplemental document, we have provided a complete introduction to the gas nonlinearity and its modeling detail. Please read it if you’re interested.
