2023/03/31 by Tigran Mansuryan, A. Tonello, Mansuryan, T. +27 · 1 citation
Chemistry · Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #FOS: Physical sciences #Optical Coherence Tomography Applications #Optics (physics.optics) #Spectroscopy and Laser Applications
paper · pdf · doi:10.48550/arxiv.2303.17891
openalex publication_date 2023/03/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We demonstrate how a narrowband pump and a broadband spectrum can be spatially multiplexed by selective coupling them in two distinct modes of a few-mode microstructure fiber. The first mode carries most of the input pump energy, and experiences spectral broadening. Whereas the second mode preserves the narrow bandwidth of the remaining part of the pump. Bimodal propagation, with a power unbalance strongly in favor of the fundamental mode, is naturally obtained by maximizing coupling into the fundamental mode of the fiber. At the fiber output, the nearly monochromatic beam and the supercontinuum carried by the two different modes are combined by a microscope objective, and used as a pump and a Stokes wave for self-referenced multiplex coherent anti-Stokes Raman scattering micro-spectroscopy. The spectral resolution, the signal-to-noise-ratio, and the possible amplification of the remaining pump beam are discussed.