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 topics dealing with the spectroscopy of real and artificial atoms, linear and nonlinear optical characteristics of quantum wells, and two-dimensional materials. The book highlights recent results of few-particle optical characteristics of artificial atoms in the framework of the exactly solvable Moshinsky model, as well as an electro-optical analog of the magneto-optical Faraday effect. In addition, a detailed study of the nucleation process, its characterization, as well as electronic and optical properties of graded composition quantum dots in the Stranski-Krastanov growth mode, is presented.