Nanjing Distinguished Lecture Series in Transformative Science and Engineering (TSE Lectures) was conceived by a visionary group of faculty and staff at the College of Engineering and Applied Sciences, Nanjing University. The main goal is to invite world-class scholars to visit Nanjing University and to speak on emerging and cross-cutting topics such as new materials, bioengineering, wearable devices, big data, optoelectronics, nanotechnology, and energy.
我们有幸邀请到法国科学院院士、国家技术研究院院士Professor Mathias Fink，作为TSE Lectures系列讲座的第六讲嘉宾。报告信息见下，欢迎各位老师和同学参加！
时间：2019年3月25日 下午15:00
地点：科技馆一楼报告厅
联系人：卢明辉教授 Email：luminghui@nju.edu.cn
题目：From Time-Reversed Waves to “Time Materials”
摘要：
Phononic crystals and Metamaterials are made from assemblies of multiple elements usually arranged in repeating patterns at scales of the order or smaller than the wavelengths of the phenomena they influence.
Because time and space play a similar role in wave propagation, wave propagation is affected as well by spatial modulation or by time modulation of the refractive index. Here we emphasize the role of time modulation. We show that sudden changes of the medium properties generate instant wave sources that emerge instantaneously from the entire wavefield and can be used to control wavefield and to revisit the way to create time-reversed waves. Experimental demonstrations of this approach will be presented.
Periodic time manipulations can also be studied in order to extend the concept of photonic crystals in the time domain. The difference between periodic time modulation and periodic spatial modulation will be emphasized and the way an antenna radiates in these two kind of situations will be discussed.
个人简介：
Mathias Fink is the George Charpak Professor at ESPCI Paris, where he founded in 1990 the Laboratory “Ondes et Acoustique” that became in 2009 the Langevin Institute. In 2008, he was elected at the College de France on the Chair of Technological Innovation. He has received several scientific awards as the CNRS Medal of innovation, the Helmholtz-Rayleigh Award of the Acoustical Society of America, the Rayleigh Award of the IEEE Ultrasonics Society and the Edwin H. Land Medal of the Optical Society of America.
Mathias Fink’s area of research is concerned with the propagation of waves in complex media and the development of numerous instruments based on this basic research. His current research interests include time-reversal in physics, wave control in complex media, super-resolution, metamaterials, medical ultrasonic imaging, ultrasonic therapy, multiwave imaging, acoustic smart objects, underwater acoustics, geophysics and telecommunications. He has developed different techniques in medical imaging (ultrafast ultrasonic imaging, transient elastography, supersonic shear imaging). He holds more than 70 patents, and he has published more than 400 peer reviewed papers and book chapters. 6 start-up companies with more than 400 employees have been created from his research.
