Professor / Joint with Argonne National Laboratory
Chris Jacobsen's research is focused on developing new methods in x-ray microscopy, and applying them to interesting problems in biology, environmental science, and materials science. Using either diffractive optics (like Fresnel zone plates fabricated using electron beam lithography), or lens-less methods where iterative phase retrieval methods are used to reconstruct an image from a coherent diffraction pattern, images with a spatial resolution of 20 nm or better can be obtained. In absorption contrast, one can combine imaging with spectroscopy to study chemical speciation at the nanoscale, or one can use fluorescence detection to study trace element distributions with parts-per-billion sensitivity. We are also developing detectors and image reconstruction algorithms that can be used to obtain quantitative phase contrast images with hard X-rays, and thus put elemental distributions into their ultrastructural context and also go from measurements of content to measurements of concentration (since concentration gradients drive chemical processes). Finally, we are interested in understanding the limitations that radiation damage presents to x-ray microscopy studies, and in developing both cryo-instrumentation and sample preparation methods to mitigate those limitations. These efforts require bright x-ray beams, so we use synchrotron radiation sources at Argonne Lab, Berkeley Lab, and elsewhere. Students in the group explore interesting problems in optical physics and in instrumentation, and get to broaden their perspective by working with collaborators from other research fields like biology, environmental science, and materials science.
Awards and Honors
- Fellow, American Association for the Advancement of Science
- Fellow, American Physical Society
- Fellow, Optical Society of America
- Presidential Faculty Fellow (White House/NSF), 1992
- International Dennis Gabor Award (Hungary), 1996
- Kurt Heinrich Award (Microbeam Analysis Society), 2001
- Junjing Deng, Youssef S.G. Nashed, Si Chen, Nicholas W. Phililips, Tom Peterka, Rob Ross, Stefan Vogt, Chris Jacobsen, and David Vine, "Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging," Optics Express23, 5348-5451 (2015). [open access online].
- Junjing Deng, David J. Vine, Si Chen, Youssef S.G. Nashed, Qiaoling Jin, Nicholas W. Phillips, Tom Peterka, Rob Ross, Stefan Vogt, and Chris Jacobsen, "Simultaneous cryo X-ray ptychography and fluorescence microscopy of green algae" PNAS 112, 2314-2319 (2015) [open access online].
- Youssef S.G. Nashed, David J. Vine, Tom Peterka, Junjing Deng, Rob Ross, and Chris Jacobsen, "Parallel ptychographic reconstruction," Optics Express 22, 32082-32097 (2014). [open access online]
- Rachel Mak, Mirna Lerotic, Holger Fleckenstein, Stefan Vogt, Stefan M Wild, Sven Leyffer, Yefim Sheynkin, and Chris Jacobsen, "Non-negative matrix analysis for effective feature extraction in x-ray spectromicroscopy," Faraday Discussions 171, 357-371 (2014). [open access online]
- Si Chen, Junjing Deng, Ye Yuan, Claus Flachenecker, Rachel Mak, Benjamin Hornberger, Qiaoling Jin, Deming Shu, Barry Lai, Joerg Maser, Chris Roehrig, Tatjana Paunesku, Sophie-Charlotte Gleber, David J. Vine, Lydia Finney, Jay Von Osinski, Michael Bolbat, Ian Spink, Zhenyang Chen, Jay Steele, David Trapp, Jeff Irwin, Michael Feser, E. Snyder, Keith Brister, Chris Jacobsen, Gayle Woloschak, and Stefan Vogt, "The Bionanoprobe: hard x-ray fluorescence nanoprobe with cryogenic capabilities," Journal of Synchrotron Radiation 21, 66-75 (2014). [open access online]
- C. Holzner, M. Feser, S. Vogt, B. Hornberger, S.B. Baines, and C. Jacobsen, “Zernike phase contrast scanning microscopy with X-rays,” Nature Physics 6, 883-887 (2010) [PDF]
- M.D. de Jonge, C. Holzner, S.B. Baines, B.S. Twining, K. Ignatyev, J. Diaz, D.L. Howard, D. Legnini, A. Miceli, I. McNulty, C.J. Jacobsen, and S. Vogt, “Quantitative 3D elemental microtomography of Cyclotella meneghiniana at 400-nm resolution,” Proceedings of the National Academy of Sciences 107, 15676-15680 (2010). [PDF]
- J. Kirz, C. Jacobsen, and M. Howells, “Soft x-ray microscopes and their biological applications.” Quarterly Reviews of Biophysics 28, 33-130 (1995). [PDF]