Boston Chapter of the IEEE Photonics Society

Abstract:  Metasurfaces, devices capable of controlling the phase and amplitude of propagating light with arrays of subwavelength structures, present a promising solution towards flat and compact optical components. In this talk, I will discuss new advances in this field enabling metasurface optical systems with functionalities rivaling and even exceeding their conventional bulk optics counterparts. In the first example, we demonstrate a single-piece metalens with an unprecedented near-180-degree field of view and aberration-free imaging over the entire field. The wide-angle metalens also features a remarkably compact and simple configuration involving only one metasurface layer on a flat substrate, and a planar focal plane ideal for optical system integration. In the second example, we further empower metasurface optics with electrically driven, low-loss optical reconfiguration capabilities by capitalizing on a broadband, bi-state transparent optical phase change material Ge2Sb2Se4Te1 (GSST) we developed. Reconfigurable meta-optical devices such as varifocal lens and tunable beam deflector are demonstrated.

Biography:  Juejun (JJ) Hu received his B.S. from Tsinghua University, China, in 2004, and his Ph.D. from Massachusetts Institute of Technology (MIT), USA, in 2009, both in materials science and engineering. He is currently an associate professor at MIT's Department of Materials Science and Engineering. Prior to joining MIT, he was an Assistant Professor at the University of Delaware, USA from 2010 to 2014. Hu has authored and coauthored more than 100 refereed journal publications. He has been recognized with the SPIE Early Career Achievement Award, the Robert L. Coble Award from the American Ceramic Society, the DARPA Young Faculty Award, the NSF CAREER Award, among others. His research primarily focuses on integrated optics and photonics. His main scientific and technical contributions include the demonstration of digital Fourier Transform (dFT) spectroscopy, mechanically flexible and stretchable photonic circuits, a panoramic dielectric metasurface lens, an optical phase change material with broadband transparency at both phases, and the first optical isolator monolithically integrated on silicon.

Location:  MIT Lincoln Laboratory Forbes Road