V.E. Zuev Institute of Atmospheric Optics

We address the problem of broadband optical scattering by microassemblies of submicron spherical silica particles functioning as an antireflective (AR) coating applied to the outer layer of a typical solar cell. Using full-wave electromagnetic modeling based on the finite element method, we perform numerical studies of the near-field spatial distribution near such microassemblies with different internal microstructures. The assemblies can be either fully ordered or possess a disordered nanotexture formed by random packing of multiple silica nanospheres (NSs). The main objective of our study is to evaluate the light transmission efficiency through the surface layer of a representative solar cell depending on the structural design of the NS-based AR coating. We show that, depending on the optical properties of the substrate, minimization of unwanted optical reflection in the spectral range of solar radiation is achieved at different angles of incidence using AR coatings consisting of subwavelength NSs arranged in a certain number of ordered (densely packed) or disordered (sparsely packed) consecutive layers.

We deal with the n-dimensional nonlinear Schrödinger equation (NLSE) with a cubic nonlocal nonlinearity and an anti-Hermitian term, which is widely used model for the study of open quantum system. We construct asymptotic solutions to the Cauchy problem for such equation within the formalism of semiclassical approximation based on the Maslov complex germ method. Our solutions are localized in the neighbourhood of a few points for every given time, i.e. form some spatial pattern. The localization points move over trajectories that are associated with the dynamics of semiclassical quasiparticles. The Cauchy problem for the original NLSE is reduced to the system of ordinary differential equations and auxiliary linear equations. The semiclassical nonlinear evolution operator is derived for the NLSE. The general formalism is applied to the specific one-dimensional and two-dimensional NLSEs with a periodic trap potential, dipole-dipole interaction, and phenomenological damping. It is shown that the long-range interactions in such model, which are considered through the interaction of quasiparticles in our approach, can lead to drastic changes in the behaviour of our asymptotic solutions.

The paper presents a semi-analytical approach to the calculation of the transmission and reflection coefficients of vector electromagnetic fields with orbital angular momentum propagating through a planar interface between two media. The model of the vector representation of the Huygens element was used to construct the vector vortex field. The Laguerre–Gauss and Bessel fields were calculated as vortex phase-distributed fields. It was shown that the transmission and reflection coefficients are the same for fields with different values of the orbital angular momentum for different gradients of the two media.

LiNbO3 plays a significant role in modern integrated photonics because of its unique properties. One of the challenges in modern integrated photonics is reducing chip production cost. Today, the most widespread yet expensive method to fabricate thin films of LiNbO3 is the smart cut method. The high production cost of smart-cut chips is caused by the use of expensive equipment for helium implantation. A prospective method to reduce the cost of photonic integrated circuits is to use sputtered thin films of lithium niobite, since sputtering technology does not require helium implantation equipment. The purpose of this review is to assess the feasibility of applying sputtered LiNbO3 thin films in integrated photonics. This work compares sputtered LiNbO3 thin films and those fabricated by widespread methods, including the smart cut method, liquid-phase epitaxy, chemical vapor deposition, pulsed laser deposition, and molecular-beam epitaxy.