题　目：Broadband Perfect Absorption of Ultrathin Conductive Films with Coherent Illumination
主讲人：Dr. Bo Hou侯波   苏州大学 物理科学与技术学院（School of Physical Science and Technology, Soochow University）
时　间：6月4日（周四），下午2:00
地　点：物理馆512会议室
 

主讲人简介：侯波，2001年7月在重庆大学应用物理系取得理学学士，2007年7月在香港科技大学物理系取得哲学博士，其后作为研究员在香港科技大学物理系工作至2008年10月，从2008年12月至2010年11月在加拿大多伦多大学电子与计算机工程系光子学专业做博士后研究，2010年12月，任苏州大学物理科学与技术学院特聘教授。学术兴趣主要集中在（1）电磁带隙功能材料，如光子晶体，电磁超材料等；（2）电磁波和声波通过亚波长缝的透射增强现象；和（3）表面等离激元及微纳光子学领域。已在Nat. Commun.、Phys. Rev. Lett.、Phys. Rev. B、Appl. Phys. Lett.等期刊发表论文40多篇。

报告简介：Absorption of microwaves by metallic conductors is typically inefficient, albeit naturally broadband, due to the huge impedance mismatch between metal and free space. Reducing metal to ultrathin profile may improve absorption efficiency, but a maximal 50% absorption limit induced by the field continuity exists. Here, we experimentally show that broadband, perfect (100%) absorption of microwaves can be realized in a single layer of ultrathin conductive film when illuminated coherently by two oppositely directed incident beams. Our experiments keep the field continuity and simultaneously break the 50% limit. Inheriting the intrinsic broadband feature of metals, complete absorption is observed to be frequency-independent in microwave experiments from 6-18GHz. Remarkably, this occurs in films with thicknesses that are at the extreme subwavelength scales, ~λ/10,000 or less. Our work proposes a way to achieve total electromagnetic wave absorption in an ultrawide spectrum of radiowaves and microwaves with a simple conductive film.