Chris Xu

Chris Xu

IBM Professor of Engineering and Director of the School of Applied and Engineering Physics
Mong Family Foundation Director of Cornell Neurotech – Engineering, Director of Cornell NeuroNex Hub


Chris Xu’s group at Cornell pioneered the development of temporal focusing and long-wavelength two- and three-photon microscopy for deep-tissue imaging. His current research areas are fiber optics and optical imaging, with major thrusts in deep-tissue imaging, laser development, and smart and efficient optical imaging. Prior to Cornell, he was a member of technical staff at Bell Labs and pioneered the development of differential phase-shift keying for long-haul fiber-optic communications. He received his Ph.D. in Applied Physics, Cornell University, and his B.S. in Physics from Fudan University. He served as the Director of Graduate Studies in Applied Physics from 2007 to 2013, and the Director of Undergraduate Studies of the School of Applied and Engineering Physics from 2014 to 2016.


Dr. Xu has chaired or served on many conference organization committees and NSF/NIH review panels. He served on the NIH NEI External Scientific Oversight Committee of the Audacious Goal Initiative and is currently serving on the Optica Biomedical Congress Strategic Planning Committee. He served as Associate Editor for Biomedical Optics Express, and is on the editorial boards of several journals. He has served and is currently serving as consultants or on the advisory boards of a number of commercial companies and academic research centers. He has published 9 book chapters and more than 300 journal and conference papers. Dr. Xu has delivered more than 300 plenary/keynote/invited conference presentations and research seminars. In addition, he has given dozens of outreach talks. He holds 25 patents on optical communications and imaging. He has won the NSF CAREER award, Bell Labs team research award, and the Tau Beta Pi and two other teaching awards from Cornell Engineering College. He received a Cornell Engineering Research Excellence Award in 2017 and was selected as an Ivy+ Provost Leadership Fellow in 2022. He is a fellow of the National Academy of Inventors and a fellow of Optica (formerly the Optical Society of America).

Research Interests

Research of the Xu Group has two main thrusts: biomedical imaging and fiber optics. We are exploring new concepts and techniques for in vivo imaging deep into scattering biological specimens, such as mouse brain. We are developing new medical endoscopes for non-invasive real-time diagnostics of tissues without any exogenous contrast agent. We are developing novel optical fibers and fiber-based devices for biomedical imaging and optical communications.

Imaging Brain Structure And Function
We develop new optical techniques that enable deep, fast, non-invasive imaging of live mouse brains. We create unique, miniature optical devices for clinical applications, such as early cancer detection, real-time biopsy, and intra-operative surgical margin assessment. Leveraging state-of-the-art telecom technology, we invent new optical fibers and fiber-based device s for biomedical imaging in collaboration with our industry partners. The close integration and cross fertilization of biomedical imaging and fiber optics take full advantage of our broad interdisciplinary expertise, and enable us to be a leader in the field of optical imaging.


Teaching Interests

Biomedical imaging and fiber optics.

Selected Publications

  • Kibaek Choe, Yusaku Hontani, Tianyu Wang, Dimitre Ouzounov, Kristine Lai, Ankur Singh, Wendy Béguelin, Ari M. Melnick and Chris Xu, “Intravital three-photon microscopy allows visualization over the entire depth of mouse lymph nodes”, Nature Immunology, 23, 330–340, (2022).
  • Yusaku Hontani, Fei Xia and Chris Xu, “Multi-color three-photon fluorescence imaging with single-wavelength excitation”, Science Advances, Vol. 7, no. 12, eabf3531, 2021.
  • Li, B., Wu, C., Wang, M., Charan, K., and Xu, C. “An adaptive excitation source for high speed multiphoton microscopy”, Nature Methods, 17, 163–166 (2020).
  • D. G. Ouzounov, T. Wang, M. Wang, D. Feng, N. G. Horton, J. C. Cruz Hernández, Y. Cheng, J. Reimer, A. Tolias, N. Nishimura, and C. Xu “In Vivo Three-Photon Imaging of Activity of GCaMP6-labeled Neurons Deep in Intact Mouse Brain”, Nature Methods, 14, 388–390, (2017).
  • C. Xu and F. W. Wise, “Recent advances in fiber lasers for nonlinear microscopy”, Nature Photonics, 7, 875–882, 2013
  • Horton, N. G., K. Wang, D. Kobat, C. Clark, F. Wise, C. Schaffer, Chris Xu.  2013. "In vivo three-photon microscopy of subcortical structures of an intact mouse brain."  Nature Photonics 7: 205-209.

Selected Awards and Honors

  • Ivy+ Provost Leadership Fellow 2022
  • Cornell Engineering Research Excellence Award 2017
  • Fellow of the National Academy of Inventors 2014
  • Fellow of the Optical Society of America (Optical Society of America) 2010
  • Excellence in Teaching Award (Cornell University - College of Engineering) 2005 and 2008
  • NSF CAREER Award (National Science Foundation) 2006
  • Tau Beta Pi teaching Award, 2004 (Cornell Society of engineers)




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