Theoretical seminar. Koshelev
9, Lomonosova str.,
‘Optical bound states in the continuum in subwavelength dielectric resonators for nonlinear nanophotonics’
Subwavelength optical resonators made of high-index dielectric materials provide efficient ways to manipulate light at the nanoscale through mode interferences and enhancement of both electric and magnetic fields. Such Mie-resonant dielectric structures have low absorption and their functionalities are limited predominantly by radiative losses. In the seminar, I will present the results of our recent paper accepted to Science . We implement a new physical mechanism for suppressing radiative losses of individual nanoscale resonators to engineer special modes with giant quality factors: optical bound states in the continuum (BICs). We demonstrate that an individual subwavelength dielectric resonator hosting a BIC mode can boost nonlinear effects increasing second-harmonic generation efficiency. Our work suggests a route to use subwavelength high-index dielectric resonators for a strong enhancement of light–matter interactions with applications to nonlinear optics, nanoscale lasers, quantum photonics, and sensors.
 Subwavelength dielectric resonators for nonlinear nanophotonics. Kirill Koshelev, Sergey Kruk, Elizaveta V. Melik-Gaykazyan, Jae-Hyuck Choi, Andrey Bogdanov, HongGyu Park, and Yuri Kivshar, Science (in print, Jan 17 2020).