Houxun Miao of the National Heart, Lung, and Blood Institute in Bethesda, MD, will present an ECE Faculty Candidate Seminar at 10am on Friday, April 21, room B02 CSL
"Novel X-Ray Imaging Systems Enabled by Nanofabrication"
X-ray imaging accounts for the majority of medical diagnostic procedures in the United States. Sensitivity, specificity and resolution are three key technical parameters of an x-ray imaging system. Enhancing the sensitivity results in a reduction of the radiation dose, which has attracted a great deal of attention. This talk presents our recent development of an ultra-sensitive x-ray interferometric imaging system enabled by nanofabrication. The development of cost-effective processes to fabricate deep submicron period hard x-ray diffraction gratings will be described. Then special focus will be given to the invention of an x-ray polychromatic far-field interferometer with the fabricated gratings, where preliminary experiments demonstrated more than an order of magnitude improvement of the sensitivity compared to the state-of-the-art grating-based Talbot-Lau interferometry technique. Potential application of the far-field interferometer in digital mammography will be discussed. A universal moiré effect to explain the physics of the polychromatic far-field interferometer and the application of this fundamental optical effect in neutron imaging will be presented. As future perspectives, I will discuss methods to improve the specificity of the x-ray interferometric imaging system for digital mammography applications and the design of novel x-ray devices and imaging systems for high resolution imaging.
Houxun Miao is currently a staff scientist at the National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH). He received his B. S. in Mechanical Engineering and M. S. in Optical Engineering from Tsinghua University in 2002 and 2004, respectively. He received his Ph.D. in Electrical and Computer Engineering from Purdue University in 2008. Prior to joining NIH in 2012, he worked as a postdoctoral research associate at the Center for Nanoscale Science and Technology (CNST), National Institute of Standards and Technology (NIST). His research interests include nanofabrication enabled novel x-ray imaging systems, optical MEMS/NEMS, nanophotonics, ultrafast optics and optical communications.