3D chiral metamaterials from terahertz to visible frequencies



Metamaterials, artificially structured nanomaterials, have enabled unprecedented phenomena such as negative refraction. However, despite the great and promising science, making practical devices based on metamaterials have been one of the most important issues due to the difficulty in fabrication. In this abstract, I will discuss recent development of hierarchical fabrication techniques for scalable large-scale and three-dimensional nanofabrication efforts to make practical metamaterials-based devices. The first example is the continuous to build reliable truly nanoscale 3D fabrication process based on ultra-accurate and precise electron-beam lithography overlay. The examples include 3D bulk negative index metamaterials, chiral metamaterials in optical frequencies and so on. Also, the recent effort of bottom-up approach using nanoparticles and selfassembled materials for isotropic 3D metamaterials will be discussed as a new direction of nanofabrication. If time allows, I will discuss the recent progress realizing a super-resolution imaging device called hyperlens in wafer-scale for high-throughput real-time imaging. With proposed hyperlens array, we show the first bio-sample imaging experimental result of super-resolution imaging on hyperlenses by combining to conventional microscopy system for imaging biomolecules. Hippocampal neuron cells are imaged by visible light through the hyperlens array with resolution down to 150 nm, beyond the diffraction limit. Such unique fabrication techniques mentioned in this talk will provide the opportunity to achieve practical metamaterial devices as the significant step making nanoscience to nanotechnology.


Junsuk Rho is currently an associate professor with a joint appointment in the Department of Mechanical Engineering and the Department of Chemical Engineering at Pohang University of Science and Technology (POSTECH), Republic of Korea. Before joining POSTECH, He received a degree his B.S. (2007) and M.S. (2008) in Mechanical Engineering at Seoul National University, Korea and the University of Illinois, UrbanaChampaign, respectively. After getting Ph.D. (2013) in Mechanical Engineering and Nanoscale Science & Engineering from the University of California Berkeley, he had worked as a postdoctoral fellow in Materials Sciences Division at Lawrence Berkeley National Laboratory and Ugo Fano Fellow in Nanoscience and Technology Division at Argonne National Laboratory. His research is focused on developing novel nanophotonic materials and devices based on fundamental physics and experimental studies of deep subwavelength light-matter interaction. Dr. Rho has published approximately 40 high impact peer-reviewed journal papers including Science, Nature Photonics and Nature Communications. He has received honorable awards including Samsung Scholarship (2008-2013), the Optical Society of America (OSA) Milton/Chang Award, the International Society for Optics and Photonics (SPIE) Scholarship (2011 & 2012), Materials Research Society (MRS) student award (2012), U.S. DOE Argonne Named Fellowship (2013-2016), Edmund Optics educational award (2015), the Optical Society of Korea young investigator award (2016), SPIE Rising Researcher Award (2017) and Korean Government MSIP Minister’s Commendation (2017).