Open AccessCompact fiber-based multi-photon endoscope working at 1700 nm
Author(s) -
Farhad Akhoundi,
Yi Qin,
N. Peyghambarian,
Jennifer K. Barton,
Khanh Kieu
Publication year - 2018
Publication title -
biomedical optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.9.002326
Subject(s) - optics , materials science , femtosecond , endoscope , lens (geology) , two photon excitation microscopy , second harmonic generation , numerical aperture , optical fiber , laser , fluorescence lifetime imaging microscopy , optoelectronics , wavelength , fluorescence , physics , medicine , radiology
We present the design, implementation and performance analysis of a compact multi-photon endoscope based on a piezo electric scanning tube. A miniature objective lens with a long working distance and a high numerical aperture (≈ 0.5) is designed to provide a diffraction limited spot size. Furthermore, a 1700 nm wavelength femtosecond fiber laser is used as an excitation source to overcome the scattering of biological tissues and reduce water absorption. Therefore, the novel optical system along with the unique wavelength allows us to increase the imaging depth. We demonstrate that the endoscope is capable of performing third and second harmonic generation (THG/SHG) and three-photon excitation fluorescence (3PEF) imaging over a large field of view (> 400 μm ) with high lateral resolution (2.2 μm ). The compact and lightweight probe design makes it suitable for minimally-invasive in-vivo imaging as a potential alternative to surgical biopsies.