Double-clad hollow core photonic crystal fiber for coherent Raman endoscope

S. Brustlein (1) , P. Berto (1) , R. Hostein (2, 1) , Patrick Ferrand (1) , C. Billaudeau (3) , D. Marguet (3) , A. Muir (4) , J. Knight (4) , H. Rigneault (1)

1 MOSAIC - MOSAIC
2 INSP - Institut des Nanosciences de Paris
3 CIML - Centre d'Immunologie de Marseille - Luminy
4 University of Bath [Bath]

Performing label free coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) in endoscope imaging is a challenge, with huge potential clinical benefit. To date, this goal has remained inaccessible because of the inherent coherent Raman noise that is generated in the fiber itself. By developing double-clad hollow core photonic crystal fiber, we demonstrate coherent anti-Stokes Raman scattering and stimulated Raman scattering in an "endoscope-like‟ scheme. Both the excitation beams and the collected CARS and SRS signals travel through the same fiber. No CARS and SRS signals are generated within the hollow core fiber even for temporally overlapping pump and Stokes beams, leading to excellent image quality. The CARS and SRS signals generated in the sample are coupled back into a high numerical aperture multimode cladding surrounding the central photonic crystal cladding. We demonstrate this scheme by imaging molecular vibrational bonds of organic crystal deposited on a glass surface.

Domaines: Optique [physics.optics]; Optique / photonique; Traitement du signal et de l'image [eess.SP]

S. Brustlein, P. Berto, R. Hostein, Patrick Ferrand, C. Billaudeau, et al.. Double-clad hollow core photonic crystal fiber for coherent Raman endoscope. Optics Express, 2011, 19 (13), pp.12562. ⟨10.1364/OE.19.012562⟩. ⟨hal-00601665⟩