A promising phenomenon such as lossy-mode resonance (LMR) is of great interest in sensor applications. Until now, this phenomenon has been shown only in fibers or planar waveguides; however, given the rapid development of such an important technological area as photonic integrated circuits (PICs), it is important to transfer LMR technology specifically to PICs. In this article, we propose the theoretical development of an integrated polymer-based LMR sensor that will also contribute to the development of hybrid organic–inorganic PICs. This work theoretically shows that LMR can be achieved using polymer SU-8 waveguides on a glass substrate, on top of which TiO₂ is deposited. In addition, the paper shows that multiple resonances can be achieved in the developed integrated sensor. The highest sensor sensitivity (about 1400 nm/RIU) was achieved with 40 nm of TiO₂. The effect of the waveguide and coating geometries, as well as the polarizations of propagating modes, is studied in this paper.

Lossy mode resonance (LMR) has garnered significant attention in sensor applications. LMR was primarily explored in fiber-based systems, however, there has been a recent upsurge in its application within planar waveguides. This article compares the LMR phenomenon in planar waveguides with the most employed coatings in the field, specifically SnO ₂ , TiO ₂ , and ITO. Additionally, the experimental findings are compared with simulations conducted using the finite element method (FEM) within the COMSOL Multiphysics environment. The novelty of this research lies in the integration of both experimental results and theoretical calculations, utilizing strong FEM simulation tools, in a single study.

Determination of the elemental composition of minerals and their derivatives at mining enterprises is important at all stages of materials processing. This paper is devoted to the results of development and application of an online XRF analysis method for monitoring mineral elements on a conveyor of mining enterprises. The paper gives an overview of mining applications in which we have successfully implemented the online analysis based on the CON-X industrial XRF analyzer in lump, ore, charge feed, cake and slag materials on conveyor belt. An evaluation of metrological characteristics achieved in these applications is presented.

This study explores an integrated tunable filter based on lossy mode resonance (LMR) in TiO_x thin films, modeled in COMSOL Multiphysics using the Wave Optics and Semiconductor modules. By exploiting the electro-optic (EO) modulation of free carrier concentration in TiO_x, the LMR wavelength can be actively tuned under an applied electric field. The results demonstrate a tuning efficiency of $4.0 \mathrm{nm}/\mathrm{V}$, which surpasses many reported EO tunable filters. Optimization studies reveal that thinner ITO electrodes and TiO_x layers enhance tuning efficiency, while the initial bulk free carrier concentration has limited influence due to the compensating effect of the Debye length. These findings extend the applicability of LMR beyond sensing, highlighting its potential for active photonic components in integrated optics.

In this study, we address the question of whether a waveguide with absorbing sidewalls can be considered pseudo free space and if the free-space transfer function is valid in such a medium. We test this hypothesis by applying a phase retrieval algorithm based on the free-space transfer function. First, optical measurements are carried out to measure the optical properties of a stack of thin films and select the parameters of simulations. Next, the propagation of light in a waveguide was simulated in COMSOL, and the phase of a wave was retrieved in MATLAB. Analysis was performed both for free-space conditions, and for a waveguide with absorbing sidewalls. The cross-correlation between the distributions of intensity under both conditions was about 0.40. The RMS error of the wave retrieved under free-space conditions was 0.378 rad, while that in the case of absorbing sidewalls was 0.323 rad, indicating successful retrieval. The successfully recovered phase of the input wave suggests that a waveguide with absorbing sidewalls can be approximated as pseudo free space and the free-space transfer function may be valid. These results may be used in future studies on how to shorten the phase retrieval of two-dimensional objects.