清华大学材料科学与工程研究院《材料科学论坛》学术报告

报告题目：Dynamic, Active, and Nonlinear Metasurfaces

报告人：Dr. Xingjie Ni（Electrical Engineering at the Pennsylvania State University）

报告时间：2019年12月26日（周四） 14:00

报告地点：清华大学逸夫技术科学楼A205学术报告厅

联系人：孙竞博老师

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报告摘要：
Metamaterials, or artificially engineered, subwavelength-scale structures, already provided us a revolutionary way to control the behavior of electromagnetic, acoustic, or thermal fields with flexibility that are unattainable with naturally available materials. Their two-dimensional counterparts – metasurfaces extend these capabilities even further. Optical metasurfaces offer fascinating possibilities of controlling light with surface-confined flat components which can manipulate the light properties directly. With the fascinating capabilities of manipulating light with judiciously designed optical nano-elements, i.e. meta-atoms, many new physics and unparalleled applications have been demonstrated, such as deflecting light to an arbitrary direction, generating optical vortex beams, enhancing the optical spin-orbit interaction, etc. Here, I would like to introduce our recent exploration on a distinct class of metasurfaces with dynamic, active, and nonlinear properties, which enable a number of novel applications. For example, with a spatiotemporal phase modulated metasurface, we truly break Lorentz reciprocity of light propagation; with dynamic phase modulation, we dramatically enhance harmonic generation on a dielectric metasurface; and with a new class of integrated metasurfaces, we can realize many new on-chip optical functions including fully controllable on-chip orbital angular momentum lasers.

Short Bio of the Speaker
Dr. Xingjie Ni is the Charles H. Fetter Assistant Professor of Electrical Engineering at the Pennsylvania State University since 2015. He is also a faculty member of the Materials Research Institute (MRI) at Penn State. Prior to that, he was a postdoctoral fellow in Professor Xiang Zhang’ group at University of California, Berkeley. He received his BS degree in Engineering Physics in 2005 and his MS degree in Automation in 2007 from Tsinghua University, Beijing, China. He completed his Ph.D. degree in Electrical and Computer Engineering at Purdue University in 2012 under Professor Vladimir Shalaev. His research interests are in nanophotonic materials and devices, which encompass metamaterials, integrated photonics, photonic sensors, nonlinear optics, and quantum optics. Dr. Ni is one of the five inaugural Moore Inventor Fellows. He also received NASA Early Career Faculty Award in 2017, Sony Faculty Innovation Award in 2018, and 3M Non-Tenured Faculty Award in 2019.