This book features selected articles based on contributions presented at the 9th International Symposium on Optics and Its Applications (OPTICS-2022) in Yerevan-Ashtarak, Armenia. The annual OPTICS symposium brings together renowned experts from all over the world working in the fields of atomic optics, plasmonics, optics of nanostructures, as well as the optics of condensed matter, and provides a perfect setting for their discussions of the most recent developments in this area. The 9th iteration in this series, dedicated to the 80th birthday of Academician Eduard Kazaryan, focuses on...