title: Nonlinear endomicroscopy using a double-clad fiber coupler.
abstract: A double-clad fiber coupler is developed to be used in two-photon-excited fluorescence endomicroscopy to replace a dichroic mirror and separate the fluorescence signal from the excitation laser beam. With the double-clad fiber coupler, the endomicroscope becomes more compact, easier to be aligned, and more stable in alignment. The double-clad fiber coupler can transmit 62% of the excitation laser beam through the core. The fluorescence collection efficiency of the double-clad fiber coupler is 34%, which is, to the best of our knowledge, the highest fluorescence collection efficiency achieved by couplers used in two-photon-excited fluorescence endomicroscopes. As a result, the contrast of endomicroscopy imaging is enhanced.
authors.affiliation: Centre for Micro-Photonics, Faculty of Engineering & Industrial Sciences, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia.
authors.forename: Hongchun
authors.initials: H
authors.lastname: Bao
authors.forename: Seon Young
authors.initials: SY
authors.lastname: Ryu
authors.forename: Byeong Ha
authors.initials: BH
authors.lastname: Lee
authors.forename: Wei
authors.initials: W
authors.lastname: Tao
authors.forename: Min
authors.initials: M
authors.lastname: Gu