title: Characterization, comparison, and choice of a commercial double-clad fiber for nonlinear endomicroscopy.
abstract: Several endomicroscope prototypes for nonlinear optical imaging were developed in the last decade for in situ analysis of tissue with cellular resolution by using short infrared light pulses. Fourier-transform-limited pulses at the tissue site are necessary for optimal excitation of faint endogenous signals. However, obtaining these transform-limited short pulses remains a challenge, and previously proposed devices did not achieve an optimal pulse delivery. We present a study of fibered endomicroscope architecture with an efficient femtosecond pulse delivery and a high excitation level at the output of commercially available double-clad fibers (DCFs). The endomicroscope incorporates a module based on a grism line to compensate for linear and nonlinear effects inside the system. Simulations and experimental results are presented and compared to the literature. Experimentally, we obtained short pulses down to 24 fs at the fiber output, what represents to the best of our knowledge the shortest pulse duration ever obtained at the output of a nonlinear endoscopic system without postcompression. The choice of the optimal DCF among four possible commercial components is discussed and evaluated in regard to multiphoton excitation and fluorescence emission.
authors.affiliation: Paris-Sud University, Orsay, IMNC Lab, UMR 8165, FrancebLimoges University, Limoges F-87060, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Lefort
authors.affiliation: Paris-Sud University, Orsay, IMNC Lab, UMR 8165, France.
authors.forename: Hussein
authors.initials: H
authors.lastname: Hamzeh
authors.affiliation: Limoges University, Limoges F-87060, FrancedXLIM Lab, UMR 7252, Limoges F-87060, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Louradour
authors.affiliation: Paris-Sud University, Orsay, IMNC Lab, UMR 8165, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pain
authors.affiliation: Paris-Sud University, Orsay, IMNC Lab, UMR 8165, FrancecParis 7-DENIS DIDEROT University, Paris F-75012, France.
authors.forename: Darine Abi
authors.initials: DA
authors.lastname: Haidar
mesh_terms: D003198:Computer Simulation; D004724:Endoscopy / Q000295:instrumentation*; D004867:Equipment Design; D005456:Fluorescent Dyes / Q000737:chemistry; D008853:Microscopy / Q000295:instrumentation*; D055100:Optical Fibers; D061848:Optical Imaging / Q000295:instrumentation*; D012235:Rhodamines / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines