Open AccessMeasurements of multiphoton action cross sections for multiphoton microscopy
Author(s) -
Cheng Li,
Nicholas G. Horton,
Ke Wang,
Shean-Jen Chen,
Chris Xu
Publication year - 2014
Publication title -
biomedical optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.5.003427
Subject(s) - microscopy , fluorescence , excitation , fluorescence microscope , two photon excitation microscopy , optics , wavelength , excitation wavelength , multiphoton fluorescence microscope , materials science , microscope , physics , quantum mechanics
We report quantitative measurements of two-, three-, and four-photon excitation action cross sections of several commonly used fluorophores and fluorescent proteins at three different excitation wavelengths of 800 nm, 1300 nm, and 1680 nm. The measured cross section values are consistent with simple quantum mechanic estimations. These values indicate that the optimum repetition rate for deep tissue 3-photon microscopy is approximately 1 to 2 MHz. We further demonstrate that it is feasible to perform 4-photon fluorescence microscopy of GFP labeled microglia in mouse brain in vivo at 1700 nm. 4-photon excitation increases the accessibility of fluorophores at the long wavelength spectral window of 1700 nm.