title: Double-clad hollow core photonic crystal fiber for coherent Raman endoscope.
abstract: 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.
authors.affiliation: Aix-Marseille Université, Institut Fresnel, Campus de Saint Jérôme, F-13013 Marseille, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Brustlein
authors.forename: Pascal
authors.initials: P
authors.lastname: Berto
authors.forename: Richard
authors.initials: R
authors.lastname: Hostein
authors.forename: Patrick
authors.initials: P
authors.lastname: Ferrand
authors.forename: Cyrille
authors.initials: C
authors.lastname: Billaudeau
authors.forename: Didier
authors.initials: D
authors.lastname: Marguet
authors.forename: Alistair
authors.initials: A
authors.lastname: Muir
authors.forename: Jonathan
authors.initials: J
authors.lastname: Knight
authors.forename: Hervé
authors.initials: H
authors.lastname: Rigneault
mesh_terms: D016477:Artifacts; D003585:Cell Biology / Q000295:instrumentation; D003460:Crystallization / Q000379:methods*; D019723:Endoscopes; D004867:Equipment Design; D008853:Microscopy / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D017711:Nonlinear Dynamics; D055100:Optical Fibers; D011133:Polysaccharide-Lyases / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014732:Vibration
chemical_list: D011133:Polysaccharide-Lyases; C080474:alpha-1,4-glucan lyase