Abstract: Holography is an optical technology that records and reconstructs spatial information of light, showing great potential for various applications such as 3D holographic imaging and optical data storage. To obtain a holographic image, various holographic devices including spatial light modulators and diffractive optical elements have shown the potential, but limited capabilities have hindered further development. In particular, current holographic devices have only a few micron scale resolution while the subwavelength scale resolution is required to eliminate diffraction orders obstructing the reconstructed holographic images. In addition, current holographic devices provide only phase or amplitude modulation, while both are required to completely reconstruct light profiles. This imperfect function in typical holographic devices causes a critical noise due to the lack of light information. Metasurfaces are planar optical devices composed of subwavelength nanostructures and have been shown unprecedented abilities to control electromagnetic waves. Hence, metasurfaces have been considered as novel holographic devices which are expected to overcome limitations of conventional ones. Recent advances in nanophotonic technology show that the metasurfaces are possible to provide not only subwavelength-scale resolutions but also any other multi-functionalities that have not been shown in conventional optics. In this talk, various metasurface platforms for holographic generation and manipulation of electromagnetic waves will be presented. General introduction of metasurface holography will be provided with its applications. Then, I will introduce the next step of those metasurfaces that provides complete control of both amplitude and phase information. Particularly, our recent work shows that X-shaped dielectric metasurfaces successfully provide full, continuous, and broadband control of both amplitude and phase of visible light at the subwavelength scale. Finally, the perspectives for the future of this area will also be discussed.
Biography: Byoungho Lee received his Ph.D. degree from the Department of Electrical Engineering and Computer Science, University of California, Berkeley in 1993. He has been in the faculty of the School of Electrical and Computer Engineering, Seoul National University since September 1994, where he is now serving as the department head. Prof. Lee is the President-Elect of the Optical Society of Korea. He is a Fellow of OSA, SPIE, IEEE, and is a Member of the Korean Academy of Science and Technology and a Senior Member of the National Academy of Engineering of Korea. He served as a Director-at-Large of OSA, chair of the Member and Education Services Council of OSA, and chair of a Technical Group and a Technical Division of OSA. Currently he is on the editorial board of Advances in Optics and Photonics and Light: Science and Applications, and is the editor-in-chief of the Journal of Information Display. He has served on the editorial board of Optics Letters, Applied Optics and Japanese Journal of Applied Physics as well as the editor-in-chief of the Journal of the Optical Society of Korea. He has received several distinguished awards such as the Scientist of the Month Award of Korea (2009), the Academic Award of the Optical Society of Korea (2006), the Academic Award of Seoul National University (2013), Special Recognition Award of the Society for Information Display (2015), and the National Science Medal of Jinbojang (2016).