Events Calendar

EE-EP Seminar - Renjie Zhou, Tuesday, March 29th at 2:00pm in EEB 132

Speaker: Renjie Zhou, George R. Harrison Spectroscopy Laboratory at MIT

Talk Title: Quantitative Phase Microscopy: a label-free platform for material metrology and biological imaging

Abstract: Advances in imaging sensors and computer chips have enabled us to record holograms on cameras and reconstruct objects information with high fidelity and fast speed. The marriage of digital holography and optical microscopy gave birth to quantitative phase imaging (QPI). QPI precisely maps the amplitude and phase information associated with the electromagnetic field scattered by an object. Recent efforts have pushed QPI instruments to achieve sensitivity better than 10-3, corresponding to less than 1 nm surface height changes, or conversely 10-4 refractive index variations in transparent biological structures. Importantly, QPI is a label-free method, without using fluorescence markers, which has opened many noninvasive imaging applications.
This talk will focus on the instrumentation and image formation of novel QPI systems and highlight their applications in two important domains, namely material metrology and biological imaging. First, I will outline the QPI potential in material characterization and wafer defect inspection. In particular, I will show our wafer metrology instrument development and its capability for densely patterned semiconductor wafer defect inspection, detecting deep sub-wavelength patterning defects in 22nm and 9nm node silicon wafers. After that, I will move my focal point to the development of QPI-based biological imaging techniques. Especially, I will talk about solving the inverse scattering problem for determining the structure of cells in 3D, which led to the invention of white-light diffraction tomography (WDT). WDT is compatible with most exiting phase contrast microscopes, thus, it can potentially complement fluorescence imaging by providing additional biophysical markers. At the end, I will discuss some potential research areas along the QPI direction, including neuron activity imaging, stem cell identification, and cell mechanics characterization.

Biography: Renjie Zhou is a postdoctoral associate at George R. Harrison Spectroscopy Laboratory at MIT, where his research centers on developing ultra-sensitive interferometric microscopy systems and high throughput 3D imaging methods for biomedical applications. Dr. Zhou received PhD in Electrical and Computer Engineering from the University of Illinois at Urbana-Champaign (UIUC) in 2014. His dissertation focused on developing wafer defect inspection instruments and solving 3D inverse scattering problems for cell imaging. Dr. Zhou has co-authored over 40 peer-reviewed journal and conference papers and filed 4 US patent applications. He has received a number of research awards including the Arnold Beckman Fellowship from the Beckman Foundation, Scholarship in Optics & Photonics and Newport Spectra - Physics Research Excellence Travel Grant from SPIE; Jean Bennett Memorial Student Travel Grant finalist from OSA; P. D. Coleman Outstanding Research Award, Yuen T. Lo Outstanding Graduate Research Award, and Sundaram Seshu International Student Fellowship from UIUC. In addition, Dr. Zhou's research work was featured in Nature, NSF, OSA, and SPIE news.

Host: EE-Electrophysics

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 132

Audiences: Everyone Is Invited

Contact: Marilyn Poplawski