Title: Optical Metasurfaces: A Path Towards Next-Generation Programmable Flat Optics

Speaker: Dr. Parikshit Moitra

Google Meet link: https://meet.google.com/hob-bxzg-ixq

Abstract: All-dielectric metasurfaces provide unique solutions for advanced wavefront manipulation of light with complete control of amplitude, phase, and polarization at sub-wavelength scales. A major limitation, however, for most of these devices is the lack of any post-fabrication tunability of their response. To overcome this limitation, I will describe in my presentation, that a promising approach is to employ a tunable medium, such as liquid crystals or phase-change-materials (PCMs), which provide a fast, low energy and volatile / non-volatile means to endow metasurfaces with a switching mechanism. Realization of complete ~2π phase modulation with high reflection/ transmission amplitude, has a promise for them to emerge as an optical component for next generation spatial light modulators (SLMs), augmented and virtual reality (AR, VR) devices, adaptive flat optics, light detection and ranging (LiDAR), dynamic holography, tunable structural colour filters and many more. Biography Dr. Parikshit Moitra went for his doctoral study in Vanderbilt University, USA in Interdisciplinary Materials Science. During his PhD, he contributed to develop the field of "all-dielectric metamaterials" by demonstrating unique optical properties such as zero-index-refraction, perfect reflection from thin metasurface layer, vortex beam generation among others. After his graduation, he moved to the UK for his post-doctoral fellowship from Optoelectronics Research Centre (ORC), University of Southampton and worked under the guidance of Prof Nikolay Zheludev, in the field of ultrafast optics. After completing two years of postdoc, he joined Institute of Materials Research and Engineering (IMRE), A*STAR in Singapore as a Scientist and have been working there since and contributing to develop programmable solutions for metasurface based next-generation flat optics. Dr. Moitra has published his research in high-impact international journals such as Nature Photonics, Advanced Materials, Light-Science & Applications, Nano Letters, Advanced Optical Materials among others. His research works have also been highlighted in Nature Materials, Nature Photonics, Light: Science & Applications and ACS C&EN, and have been cited in major review articles in his field.