Related Experiment Video
Updated: May 11, 2026

High-resolution Fiber-optic Microendoscopy for in situ Cellular Imaging
Published on: January 11, 2011
Three-photon excited fluorescence imaging of unstained tissue using a GRIN lens endoscope
David M Huland1, Kriti Charan, Dimitre G Ouzounov
1School of Applied and Engineering Physics, Cornell University, 146 Clark Hall, Ithaca, NY 14853, USA ; These authors contributed equally to this work.
Abstract:
We present a compact and portable three-photon gradient index (GRIN) lens endoscope system suitable for imaging of unstained tissues, potentially deep within the body, using a GRIN lens system of 1 mm diameter and 8 cm length. The lateral and axial resolution in water is 1.0 μm and 9.5 μm, respectively. The ~200 μm diameter field of view is imaged at 2 frames/s using a fiber-based excitation source at 1040 nm. Ex vivo imaging is demonstrated with unstained mouse lung at 5.9 mW average power. These results demonstrate the feasibility of three-photon GRIN lens endoscopy for optical biopsy.
