Background-penalty-free waveguide enhancement of CARS signal in air-filled anti-resonance hollow-core fiber

We study coherent anti-Stokes Raman spectroscopy in air-filled anti-resonance hollow-core photonic crystal fiber, otherwise known as revolver fiber. We compare the vibrational coherent anti-Stokes Raman signal of N-2, at similar to 2331 cm(-1), generated in ambient air (no fiber present), with the one generated in a 2.96 cm of a revolver fiber. We show a similar to 170 times enhancement for the signal produced in the fiber, due to an increased interaction path. Remarkably, the N-2 signal obtained in the revolver fiber shows near-zero non-resonant background, due to near-zero overlap between the laser field and the fiber cladding. Through our study, we find that the revolver fiber properties make it an ideal candidate for the coherent Raman spectroscopy signal enhancement. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this study, we investigated the application of coherent anti-Stokes Raman spectroscopy in revolver fiber. We found that revolver fiber can significantly enhance the vibrational coherent anti-Stokes Raman signal of nitrogen and produce a signal with near-zero non-resonant background.