arXiv subjects

Dmitrii N. Maksimov

Publications and source records attributed to Dmitrii N. Maksimov.

At least 19 recordsLinked to original sources

arXiv2026

Exceptional Points in Photonics: From Non-Hermitian Physics to Applications

Open photonic systems provide a versatile platform for non-Hermitian physics, enabling control over complex spectra, transport, and light-matter interactions. Exceptional points (EPs), at which eigenvalues and eigenvectors coalesce and the governing operator becomes defective, play a central role because they combine branch-point spectral topology, nonanalytic perturbative response, and controllable eigenstate conversion. This Review provides a unified framework for EP photonics by systematically distinguishing exceptional degeneracies according to the underlying operator, spectral variable, boundary conditions, and experimentally accessible observables. We discuss Hamiltonian EPs, absorbing EPs associated with scattering zeros, real-frequency scattering-matrix and Jones-matrix EPs, Bloch and Floquet EPs, and Liouvillian EPs in open quantum systems. We review their spectral topology, static and dynamical encircling, higher-order exceptional structures, and coexistence with bound states in the continuum, together with applications in sensing, lasing, coherent absorption, directional scattering, polarization and wavefront control, nonlinear optics, optical storage, nonreciprocal photonics, and quantum photonics. We also critically assess the current limitations, practical challenges, and future perspectives of EP-based photonic technologies, with particular attention to robustness, noise, scalability, and experimentally measurable performance.

physics.optics↗

arXiv2025

Temporal coupled mode theory for high-$Q$ resonances in dielectric metasurfaces

In this work, we propose a coupled mode theory for resonant response from quasi-guided modes in periodic dielectric metasurfaces. First, we derived a generic set of constraints imposed onto the parameters of the temporal coupled mode theory by energy conservation and time-reversal symmetry in an invariant form that allows for asymmetry between the coupling and decoupling coefficients. The proposed approach is applied to the problem of Fano resonances induced by isolated quasi-guided modes in the regime of specular reflection. Our central result is a generic formula for the line-shape of the Fano resonance in transmittance for the lossless metasurfaces in the framework of 2D electrodynamics. We consider all possible symmetries of the metasurface elementary cell and uncover the effects that the symmetry incurs on the profile of the Fano resonance induced by an isolated high-$Q$ mode. It is shown that the proposed approach correctly describes the presence of robust reflection and transmission zeros in the spectra as well as the spectral signatures of bound states in the continuum. The approach is applied to uniderictionally guided resonant modes in metasurfaces with an asymmetric elementary cell. It is found that the existence of such modes and the transmittance in their spectral vicinity are consistent with the theoretical predictions. Furthermore, the theory predicts that a uniderictionally guided resonant mode is dual to a counter-propagating mode of a peculiar type which is coupled with the outgoing wave on both sides of the metasurface but, nonetheless, exhibits only a single-sided coupling with incident waves.

physics.optics↗

arXiv2025

Quantum Noise Suppression in Non-Hermitian Resonators at Exceptional Point

We investigate the impact of quantum noise on non-Hermitian resonators at an exceptional point (EP). The system's irreversible Markovian dynamics is modeled using the Lindblad master equation, which accounts for the incoherent pump, radiative losses, and external monochromatic field. An exact analytic solution is derived in the form of the characteristic function of the Husimi distribution, enabling the calculation of all quantum mechanical observables associated with the bosonic degrees of freedom. Our analysis reveals that quantum noise strongly influences the system's response when the system exhibits $\mathcal{P}\mathcal{T}$-symmetry. Out of the $\mathcal{P}\mathcal{T}$-symmetric regime, however, the system demonstrates stability within a specific parametric domain, where the effects of quantum noise on the signal-to-noise ratio can be mitigated by increasing the external field.

quant-ph↗

arXiv2024

Electrically controlled laser generation in a photonic crystal - liquid crystal - metal microcavity

A comprehensive approach for simulating lasing dynamics in a liquid crystal based laser is presented. The approach takes into account the transformation of the liquid crystal structure caused by applied voltage. In particular, it allows us to explicitly account for a resonant mode frequency shift in the laser equations. The laser dynamic is described by a set of coupled non-linear differential equations for dye polarizations, population densities and the electromagnetic fields. The proposed model is applied to a photonic crystal$-$metal microcavity filled with a resonant nematic liquid crystal layer doped with a dye. The calculated lasing spectra governed by external electric field are verified in comparison with measured spectra.

physics.optics↗

arXiv2023

Enhanced light absorption in Tamm metasurface with a bound state in the continuum

We consider light absorption in a germanium grating placed on top of photonic-crystalline substrate. Such a system supports an optical Tamm state decoupled from the continuous spectrum with its frequency within the photonic band gap. We have demonstrated that application of the Tamm state makes in possible to engineer extremely narrow absorber which provides a 100% absorption in a semiconductor grating in the critical coupling regime. The proposed design may be used at both normal and oblique incidence at the telecom wavelength.

physics.optics↗

arXiv2022

Fabry-Perot Bound States in the Continuum in an Anisotropic Photonic Crystal

An anisotropic photonic crystal containing two anisotropic defect layers is considered. It is demonstrated that the system under can support a Fabry-Perot bound state in the continuum (FP-BIC). A fully analytic solution of the scattering problem as well as a condition for FP-BIC have been derived in the framework of the temporal coupled-mode theory.

physics.optics↗

arXiv2022

Non-Markovian master equation for quantum transport of fermionic carriers

We propose a simple, yet feasible, model for quantum transport of fermionic carriers across tight-binding chain connecting two reservoirs maintained at arbitrary temperatures and chemical potentials. The model allows for elementary derivation of the master equation for the reduced single particle density matrix in a closed form in both Markov and Born approximations. In the Markov approximation the master equation is solved analytically, whereas in the Born approximation the problem is reduced to an algebraic equation for the single particle density matric in the Redfield form. The non-Markovian equation is shown to lead to resonant transport similar to Landauer's conductance.

cond-mat.quant-gas↗

arXiv2021

Enhanced sensitivity of an all-dielectric refractive index sensor with optical bound state in the continuum

The sensitivity of a refractive index sensor based on an optical bound state in the continuum is considered. Applying Zel'dovich perturbation theory we derived an analytic expression for bulk sensitivity of an all-dielectic sensor utilizing symmetry protected in-$Γ$ optical bound states in a dielectric grating. The upper sensitivity limit is obtained. A recipe is proposed for obtaining the upper sensitivity limit by optimizing the design of the grating. The results are confirmed through direct numerical simulations.

physics.optics↗

arXiv2021

Bound state in the continuum in an anisotropic photonic crystal supported by full-wave phase plate

We consider bound states in the continuum (BICs) in a 1D multilayered system of an anisotropic defect layer embedded into an anisotropic photonic crystal. We analytically demonstrate that an anisotropic defect layer embedded into anisotropic photonic crystal supports accidental BICs. These BICs can be transformed to a high-Q resonances by variation of one of the system's parameters. At the same time the BICs are remarkably robust in a sense that a true BIC can be recovered by further tuning any of the other system's parameters leading to tunability of the resonance position.

physics.optics↗

arXiv2021

Resonant transmission of fermionic carriers: comparison between solid-state physics and quantum optics approaches

We revisit the phenomenon of the resonant transmission of fermionic carriers through a quantum device connected to two contacts with different chemical potentials. We show that, besides the traditional in solid-state physics Landauer-Büttiker approach, this phenomenon can be also described by the non-Markovian master equation for the reduced density matrix of the fermions in the quantum device. We identify validity regions of both approaches in the system parameter space and argue that for large relaxation rates the accuracy of the latter approach greatly exceeds the accuracy of the former.

quant-ph↗

arXiv2020

Refractive index sensing with optical bound states in the continuum

We consider refractive index sensing with optical bounds states in the continuum (BICs) in dielectric gratings. Applying a perturbative approach we derived the differential sensitivity and the figure of merit of a sensor operating in the spectral vicinity of a BIC. Optimisation design approach for engineering an effective sensor is proposed. An analytic formula for the maximal sensitivity with an optical BIC is derived. The results are supplied with straightforward numerical simulations.

physics.optics↗

arXiv2020

Critical coupling vortex with grating-induced high quality optical Tamm states

We investigate optical Tamm states supported by a dielectric grating placed on top of a distributed Bragg reflector. It is found that under certain conditions the Tamm state may become a bound state in the continuum. The bound state, in its turn, induces the effect of critical coupling with reflectance amplitude reaching an exact zero. We demonstrate that the critical coupling point is located in the core of a vortex of the reflection amplitude gradient in space of wavelength and angle of incidence. The emergence of the vortex is explained by the coupled mode theory.

physics.optics↗

arXiv2020

Low Threshold Bound State in the Continuum Lasers in Hybrid Lattice Resonance Metasurfaces

Bound states in the continuum (BICs) have attracted much attention in recent years due to the infinite quality factor (Q-factor) resonance and extremely localized field. In this study, BICs have been demonstrated by dielectric metasurfaces with hybrid surface lattice resonance (SLR) in the experiment. By breaking the symmetry of geometry, SLR can be easily switched between BICs and quasi-BICs. Comparing with literature, switching between BICs and quasi-BICs is usually accompanied by wavelength shift. Here, a design rule is proposed to prevent the wavelength shift when the Q-factor is changing. Also, such a design also makes subsequent identification of the laser threshold more credible. Due to the high Q-factor, low threshold laser is one of the intuitive applications of BICs. Utilize the high localized ability of BICs, low threshold BICs laser can be achieved by the dielectric metasurface immersed with Rhodamine 6G. Interestingly, due to the high Q-factor resonance of BICs, the laser signals and images can be observed in almost transparent samples. Not only the BICs laser is demonstrated in the experiment, but also the mechanism of BICs is deeply analyzed. This study can help readers better understand this novel feature of BICs, and provide the way for engineer BICs metasurfaces. The device can provide various applications, including laser, optical sensing, non-linear optics enhancement, and single-photon source.

physics.app-ph↗

arXiv2020

Optical bistability with bound states in the continuum in dielectric gratings

We consider light scattering by dielectric gratings supporting optical bound states in the continuum. Due to the presence of instantaneous Kerr nonlinearity the critical field enhancement in the spectral vicinity of the bound state triggers the effect of optical bistability. The onset of bistability is explained theoretically in the framework of the temporal coupled mode theory. As the central result we cast the problem into the form of a singly field-driven nonlinear oscillator. The theoretical results are verified in comparison against full-wave numerical simulations.

physics.optics↗

arXiv2020

Fano feature induced by a bound state in the continuum via resonant state expansion

We consider light scattering by an anisotropic defect layer embedded into anisotropic photonic crystal in the spectral vicinity of an optical bound state in the continuum (BIC). Using a resonant state expansion method we derive an analytic solution for reflection and transmission amplitudes. The analytic solution is constructed via a perturbative approach with the BIC as the zeroth order approximation. The solution is found to describe the collapsing Fano feature in the spectral vicinity of the BIC. The findings are confirmed via comparison against direct numerical simulations with the Berreman transfer matrix method.

physics.optics↗

arXiv2019

Quantum state of the fermionic carriers in a transport channel connecting particle reservoirs

We analyze quantum state of fermionic carriers in a transport channel attached to a particle reservoir. The analysis is done from the first principles by considering microscopic models of the reservoir and transport channel. In the case of infinite effective temperature of the reservoir we demonstrate a full agreement between the results of straightforward numerical simulations of the system dynamics and solution of the specified master equation on the single-particle density matrix of the carriers in the channel. This allows us to predict the quantum state of carriers in the case where transport channel connects two reservoirs with different chemical potentials.

cond-mat.quant-gas↗

arXiv2019

Nonlinear response from optical bound states in the continuum

We consider nonlinear effects in scattering of light by a periodic structure supporting optical bound states in the continuum. In the spectral vicinity of the bound states the scattered electromagnetic field is resonantly enhanced triggering optical bistability. Using coupled mode approach we derive a nonlinear equation for the amplitude of the resonant mode associated with the bound state. We show that such an equation for the isolated resonance can be easily solved yielding bistable solutions which are in quantitative agreement with the full-wave solutions of Maxwell's equations. The coupled mode approach allowed us to cast the the problem into the form of a driven nonlinear oscillator and analyze the onset of bistability under variation of the incident wave. The results presented drastically simplify the analysis nonlinear Maxwell's equations and, thus, can be instrumental in engineering optical response via bound states in the continuum.

physics.optics↗

arXiv2018

Avoided crossings and bound states in the continuum in low-contrast dielectric gratings

We consider bound states in the continuum (BICs) in low-contrast dielectric gratings (DGs). It is demonstrated that the BICs originate from the reduced guided modes on the effective dielectric slab with the permittivity equal to the average permittivity of the DG. In case of isolated resonances the positions of BICs can be found from two-wave dispersion relationships for guided leaky modes. In the case of the degeneracy between the two families of leaky modes the system exhibits an avoided crossing of resonances. In the spectral vicinity of the avoided crossing the transmittance as well as the emergence of BICs is described in the framework of the generic formalism by Volya and Zelevinsky [Physical Review C 67, 054322 (2003)] with a single fitting parameter.

physics.optics↗