title: Signal enhancement in multiphoton imaging by the use of coated glass substrates.
abstract: In nonlinear optical imaging of biological specimens, more than half of the generated luminescence signal is lost, when signal collection is performed in the epi-illuminated geometry. In this study, we enhanced the collected luminescence signal by the use of alternating multiply-coated layers of tantalum pentoxide (Ta2O5) and silicon dioxide (SiO2) on standard microscope cover glasses that has high transmission in the near-infrared wavelength region and high reflection of the visible, luminescence signal. Our coating is biocompatible, allows visual examination of the specimens and optimize collection of the luminescence signal. We demonstrated this approach on a number of specimens including sulforhodamine solution, fluorescence microspheres, and labeled 3T3 cells. In all cases, the use of coated cover glass enhanced signal, optimally by a factor of about 2. Image analysis of labeled 3T3 cells also shows signal enhancement did not contribute to additional photobleaching. Our results show that properly designed coated cover glass can enhance detected signal in multiphoton microscopy and result in improved image quality.
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Sheng-Lin
authors.initials: SL
authors.lastname: Lee
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Han-Wen
authors.initials: HW
authors.lastname: Guo
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan ; Y. F. Chen at yfchen@phys.ntu.edu.tw.
authors.forename: Yang-Fan
authors.initials: YF
authors.lastname: Chen
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan ; Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei 100, Taiwan ; Center of Quantum Science and Engineering, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Chen-Yuan
authors.initials: CY
authors.lastname: Dong
keywords: (000.2700) General science; (300.6410) Spectroscopy, multiphoton