Nonlinear optical phenomena are central to a myriad of applications in light sources and microscopy. Nonlinear optical effects, such as harmonic generation, frequency mixing and spontaneous parametric down conversion (SPDC) are fundamentally enhanced in materials with a high refractive index, as well as by the presence of resonant photonic environment. These conditions are automatically fulfilled in resonant dielectric metasurfaces, which has triggered large interest in nonlinearity enhancement at the nanoscale. Despite their small volume, the dielectric metasurfaces can enhance the nonlinear frequency conversion to a level similar to millimetre-scale nonlinear crystals. Importantly, the nanostructuring enables properties not possible in bulk crystals, including engineering of the directionality of emission and polarisation of the emitted light. In this talk, I will review the recent advances in the field of nonlinear metasurfaces for enhancement of nonlinear frequency conv ersion and shaping of the directionality of emission. In particular, I will focus on the control of forward to backward second harmonic emission in single-crystal transition-metal-dichalcogenide metasurfaces. I will further present possible applications of nonlinear metasurfaces for nonlinear upconversion imaging and generation of non-classical photon states with engineered momentum entanglement.
Dragomir Neshev is the Director of the Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems (TMOS) and a Professor in Physics at the Australian National University (ANU). He received a PhD degree from Sofia University, Bulgaria in 1999. Since then, he has worked in the field of optics at several research centres around the world and joined ANU in 2002. He is the recipient of several awards and honours, including a Highly Cited Researcher (Web of Science, 2021), a Queen Elizabeth II Fellowship (ARC, 2010), and a Marie-Curie Individual Fellowship (European Commission, 2001). His activities span over several branches of optics, including periodic photonic structures, singular optics, plasmonics, and optical metasurfaces.
As part of the outreach activities of Center for Millimeter and Microwave Research, under the auspices of pCoE, at IIT Madras and on the completion of 60 years of Microwave Laboratory, Department of Physics, IIT Madras, the SIXTH lecture of the Webinar Series on Millimeter and Microwave Research
Link for Attendees: https://iitmadras.webex.com/iitmadras/j.php?MTID=m0004d38fe78dd22811282713247d5ae3 (ShortURL: https://bit.ly/3e0ZSk2) Webinar password: HSB222