title: Simple approach to three-color two-photon microscopy by a fiber-optic wavelength convertor.
abstract: A simple approach to multi-color two-photon microscopy of the red, green, and blue fluorescent indicators was reported based on an ultra-compact 1.03-μm femtosecond laser and a nonlinear fiber. Inside the nonlinear fiber, the 1.03-μm laser pulses were simultaneously blue-shifted to 0.6~0.8 μm and red-shifted to 1.2~1.4 μm region by the Cherenkov radiation and fiber Raman gain effects. The wavelength-shifted 0.6~0.8 μm and 1.2~1.4 μm radiations were co-propagated with the residual non-converted 1.03-μm pulses inside the same nonlinear fiber to form a fiber-output three-color femtosecond source. The application of the multi-wavelength sources on multi-color two-photon fluorescence microscopy were also demonstrated. Overall, due to simple system configuration, convenient wavelength conversion, easy wavelength tunability within the entire 0.7~1.35 μm bio-penetration window and less requirement for high power and bulky light sources, the simple approach to multi-color two-photon microscopy could be widely applicable as an easily implemented and excellent research tool for future biomedical and possibly even clinical applications.
authors.affiliation: College of Photonics, National Chiao-Tung University, Taiwan; Equal contribution.
authors.forename: Kuen-Che
authors.initials: KC
authors.lastname: Li
authors.affiliation: Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Taiwan; Institute of Biotechnology, National Cheng Kung University, Taiwan; Research Center of Excellence in Regenerative Medicine, National Cheng Kung University, Taiwan; Equal contribution.
authors.forename: Lynn L H
authors.initials: LL
authors.lastname: Huang
authors.affiliation: Institute of Biotechnology, National Cheng Kung University, Taiwan.
authors.forename: Jhih-Hao
authors.initials: JH
authors.lastname: Liang
authors.affiliation: College of Photonics, National Chiao-Tung University, Taiwan.
authors.forename: Ming-Che
authors.initials: MC
authors.lastname: Chan
keywords: (060.4370) Nonlinear optics, fibers; (110.4234) Multispectral and hyperspectral imaging; (180.2520) Fluorescence microscopy; (180.4315) Nonlinear microscopy; (320.7110) Ultrafast nonlinear optics