Coherent anti-Stokes Raman scattering microscopy through a multimode fiber endoscope

0535569 - ÚPT 2021 RIV US eng C - Conference Paper (international conference)
Traegaardh, Johanna - Pikálek, Tomáš - Šerý, Mojmír - Akimov, D. - Meyer, T. - Poppe, J. - Čižmár, Tomáš
Coherent anti-Stokes Raman scattering microscopy through a multimode fiber endoscope.
Biomedical Spectroscopy, Microscopy, and Imaging 2020. Proceedings of SPIE. Vol. 11359. Bellingham: SPIE, 2020, č. článku 162267. ISBN 978-151063490-9. ISSN 0277-786X.
[Biomedical Spectroscopy, Microscopy, and Imaging 2020. France (FR), 06.04.2020-10.04.2020]
R&D Projects: GA MŠMT EF15_003/0000476; GA MŠMT(CZ) LO1212; GA MŠMT ED0017/01/01
Institutional support: RVO:68081731
Keywords : adaptive optics * CARS * endoscopy * microscopy * multi-photon microscopy * Raman
OECD category: Optics (including laser optics and quantum optics)
https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11359/1135907/Coherent-anti-Stokes-Raman-scattering-microscopy-through-a-multimode-fiber/10.1117/12.2555080.short

Advanced wavefront-shaping methods can be used to transform a simple multimode fiber into an ultra-thin laser scanning microscope. Here, we extend this technique to label-free non-linear microscopy with chemical contrast using coherent anti-Stokes Raman scattering (CARS) through a multimode fiber endoscope, which opens up new avenues for instant and in-situ diagnosis of potentially malignant tissue. We use a commercial, 125 μm diameter, 0.29 NA, GRIN fiber as the endoscopic probe. Wavefront shaping on a spatial light modulator is used to create a focus, where the 1-2 ps long pump and Stokes pulses are overlapped in time, which is scanned behind the fiber facet across the sample. The chemical selectivity is demonstrated by imaging 2 μm polystyrene and 2.5 μm PMMA beads with per pixel integration time as low as 1 ms for epi-detection. Epi-detection through the fiber is possible despite the fact that the CARS signal is emitted mainly in the forward direction, away from the fiber facet. Detecting the back-scattered signal from the underlying tissue, requires a large detector aperture to be efficient. By detecting through both the core and the cladding of the fiber, we obtain sufficient detection efficiency. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
Permanent Link: http://hdl.handle.net/11104/0313564