Scanning fiber-optic nonlinear endomicroscopy with miniature aspherical compound lens and multimode fiber collector

• Published in: Optics letters Vol. 34; no. 7; p. 953
• Main Authors: Wu, Yicong, Xi, Jiefeng, Cobb, Michael J, Li, Xingde
• Format: Journal Article
• Language: English
• Published: United States 01.04.2009
• Subjects: Animals; Color; Equipment Design; Fiber Optic Technology - instrumentation; Fiber Optic Technology - methods; Image Interpretation, Computer-Assisted - instrumentation; Image Interpretation, Computer-Assisted - methods; Lenses; Light; Microscopy - instrumentation; Microscopy - methods; Microscopy, Fluorescence - instrumentation; Microscopy, Fluorescence - methods; Optical Fibers; Optics and Photonics; Rats; Signal Processing, Computer-Assisted - instrumentation; Tendons - pathology
• ISSN: 0146-9592
• DOI: 10.1364/OL.34.000953

A flexible scanning fiber-optic endomicroscope using a miniature compound lens and a multimode-fiber (MMF) collector was developed for two-photon fluorescence (TPF) and second-harmonic generation (SHG) imaging. The compound lens consisted of a pair of aspherical lenses and exhibited reduced chromatic aberration compared with gradient-index lenses, thus increasing the TPF/SHG collection efficiency. The introduction of a short MMF collector at the distal end of the double-clad fiber of the endomicroscope further mitigated the adverse influence of chromatic aberration of the lens and enhanced the TPF/SHG collection efficiency. Both ray-tracing simulations and experiments on TPF imaging of fluorescent beads and SHG imaging of rattail tendon demonstrated approximately nine (approximately four) times improved collection efficiency for TPF (SHG) with the new endomicroscope design that utilized a compound lens and an MMF collector.