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Igor V. Minin

Publications and source records attributed to Igor V. Minin.

At least 19 recordsLinked to original sources

Super-Resonance: Interference-Driven Suppression of Radiative Decay Across Wave Physics

Super-resonance has been coined independently for collective modes of acoustic cavity arrays (Tolstoy), extreme high-$Q$ states of dielectric resonators in photonics, and magnon-polaron bound states in magnonics, and is now applied interchangeably to physically distinct phenomena. We organise this review around the one usage admitting a precise, field-agnostic definition: a mode whose radiative linewidth is driven toward zero by destructive interference among its radiation channels, $γ_{\rm rad}/γ_{\rm rad}^{\rm cl}\to0$, while the bare single-channel coupling remains large. The canonical realisation is the Friedrich-Wintgen scenario of two modes sharing a continuum. The same non-Hermitian eigenvalue structure recurs in Tolstoy's acoustic arrays, photonic bound states in the continuum and quasi-BIC supercavity modes, anapoles, dark modes of coherent perfect absorbers, parity-time-symmetric devices near exceptional points, magnonic dark modes, and topological edge modes. We survey these realisations field by field and distil transferable design rules and figures of merit. We then disambiguate super-resonance from two families sharing the "super-" prefix: coherent enhancement, in which coupling to the continuum is collectively increased rather than suppressed (Dicke super-radiance, superscattering, whispering-gallery modes); and integer-commensurability locking (mean-motion, wave-particle, and Floquet resonances). Amplification, as in black-hole super-radiance, is likewise distinguished.

physics.optics

Photonic Jet with Tunable Focus Based on Water Droplets Freezing from the Outside In

Water droplets are a perspective highly abundant phase-change material to realize tunable optical lenses. We demonstrated for the first time that freezing mesoscale water droplet could be use as tunable optical lens, such that freezing becomes an asset despite both the low absolute values of the refractive indices of the shell and core materials and their optical contrast. It was shown that the dielectric shell of mesoscale water droplet in the form of solid ice allows controlling both the maximum field intensity and the focus position of the formed photonic nanojet. The formation of ice with air bubbles during the freezing of a water droplet is appropriate for a dynamic increase in the range of change of the focal position compared to solid ice. The proposed concept of a tunnelable spherical lens based on a freezing water drop can be used for microscopy, optical traping in "green" mesotronics.

physics.optics

Future green technology: freezing water micro-droplet as an all-optical switch based on time domain photonic hook

Here we show that mesoscale freezing water droplet with low Bond number can behave as fully biocompatible natural microlenses to form the photonic hook in application to tunable optical switch. We first introduce and demonstrated the basic concepts of all-optical switch without changes in the wavelength of illumination of a particle or any moving parts involved. The principle of operation of the switch based on the temperature-induced phase change inside water droplet refractive index. Simulation shows that the optical isolation of switched channels for an optical switch with linear dimensions of about 15λ3, based on freezing water droplet, can reach 10 dB during the temperature variation at fixed wavelength. The freezing mesoscale droplets acting as time domain photonic hook generator open the intriguing route for full optical switching in a multifunctional green electronics tool for sensing, integrated optics and optical computers.

physics.optics

Photonic Hook with Modulated Bending Angle Formed by Using Triangular Mesoscale Janus Prisms

In this study, we propose a novel design of the triangular mesoscale Janus prisms for the generation of the long photonic hook. The numerical simulations based on the finite-difference time-domain method are used to examine the formation mechanism of the photonic hook. The electric intensity distributions near the micro-prisms are calculated for operating at different re-fractive indices and spaces of the two triangular micro-prisms. The asymmetric vortexes of in-tensity distributions result in the long photonic hook with large bending angle. The length and the bending angle of the photonic hook are efficiently modulated by changing the space be-tween the two triangular micro-prisms. Moreover, the narrow width of the photonic hook is achieved beyond the diffraction limit. The triangular Janus micro-prisms have high potential for practical applications in optical tweezers, nanoparticle sorting and manipulation and photonic circuits.

physics.optics

Multi-directional cloak design by all dielectric unit-cell optimized structure

In this manuscript, we demonstrate the design and experimental proof of an optical cloaking structure which multi-directionally conceals a perfectly electric conductor (PEC) object from an incident plane wave. The dielectric modulation around the highly reflective scattering PEC object is determined by an optimization process for multi-directional cloaking purposes. And to obtain the multi-directional effect of the cloaking structure, an optimized slice is mirror symmetrized through a radial perimeter. Three-dimensional (3D) finite-difference time-domain method is integrated with genetic optimization to achieve cloaking design. In order to overcome the technological problems of the corresponding devices in the optical range and to experimentally demonstrate the proposed concept, our experiments were carried out on a scale model in the microwave range. The scaled proof-of-concept of proposed structure is fabricated by 3D printing of polylactide material, and the brass metallic alloy is used as a perfect electrical conductor for microwave experiments. A good agreement between numerical and experimental results is achieved. The proposed design approach is not restricted only to multi-directional optical cloaking but can also be applied for different cloaking scenarios dealing with electromagnetic waves in nanoscales as well as other types of such as acoustic waves. Using nanotechnology, our scale proof-of-concept research will take the next step towards the creation of "optical cloaking" devices.

physics.app-ph

Highly curved reflective W-shape and J-shape photonic hook induced by light interaction with partially coated microfluidic channels

Photonic hook (PH) is a new type of artificial self-bending beam focused by a dielectric particle-lens with a curved waist smaller than the wavelength, which has the potential to revolutionize mesoscale photonics in many applications, e.g., optical trapping, signal switching, imaging, etc. In this paper, we discover a new mechanism that the highly curved PHs can be realised by the light interaction with the fully or partially metal-coated microchannels. The generated W-shaped and J-shaped PHs have bending angles exceeding 80-degree. Compared to other PH setups, the proposed design has a larger range to flexibly control the bending angle through the coating process and can be easily integrated with the established microfluidic systems.

physics.optics

Cascades of Fano Resonances in Scattering by a Mesoscale Spherical Particle in the Superresonance Mode

Broadband light illumination of a mesoscale dielectric sphere makes it possible to reveal new effects that associated with super resonance mode. These include the possibility of generating high-order Fano resonance cascades. The quality factor has the order Q=10^7. Super-resonance-enabled subdiffraction fields localization by mesoscale dielectric sphere under broadband light illuminations (e.g., at wavebands of 400 - 700 nm for refractive index of sphere n=1.5-1.9 and 1500 - 1600 nm for n=3.47) have been investigated. The conditions for the quasi-periodicity of superresonance peaks are established. The dependence of the amplitude modulation of Fano cascades on the refractive index of the sphere is shown. These results are important in deep understanding of physics of the super-resolution mechanism related to superresonance mode and will find great potential applications in many other area.

physics.optics

Super-resonance effect for high-index sphere immersed in water

Recently, we showed that dielectric mesoscale spheres support super-resonance effect, i.e. high-order Mie resonance modes with giant field enhancement. The presence of the surrounding medium leads to a significant influence in the intensity of the electric and magnetic fields in the particle. In this paper, we show that this effect can be used for highly precise control of the effective refractive index of a medium, such as water. We show that a change in the water temperature by dT=0.0106 C (or the effective refractive index of the medium by 2e-6) leads to a twofold drop in electric field intensity. All the presented results are strictly within the framework of the classical Mie theory without any modifications. A detailed study of the ranges of values of the size parameters of a spherical particle of the order of 10, which had previously been neglected, made it possible to reveal a new, unusual physics of the phenomenon.

physics.optics

Influence of the Environment on the Effect of Super Resonance in Mesoscale Dielectric Spheres

Dielectric mesoscale spheres have aroused strong interest because of their potential to localize light at deep subwavelength volume and to yield extremal internal magnetic and/or electric field enhancements. Recently, we showed that such particle could support high-order Mie resonance modes with giant field localization and enhancement. Optimizing the internal fields appears as a key challenge for enhancing wave matter interactions in dielectric mesoscale particles. However, a dielectric particle is always located in some medium, and not in a vacuum. Moreover, the question is how much the environment medium affects the internal field intensities enhancement in the super-resonance effect. Based on Mie theory we show for the first time that the presence of the environment leads to a significant decrease in the intensity of the field in the particle. Thus, the study of the effect of super-resonance becomes meaningless without taking into account the environment. However, a greater enhancement of the internal field is found for the blue-shifted Mie size parameter of the sphere when the particle, for example, is in air rather than in vacuum.

physics.optics

The super resonance effect paves the way for a new type of refractive index sensor concept based on a mesoscale dielectric sphere

Recently, we showed that dielectric mesoscale spheres could support so-called super-resonance effect, i.e. high-order Mie resonance modes with giant field localization and enhancement. Due to the presence of the surrounding medium leads to a significant influence in the intensity of the field in the particle, based on Mie theory we show for the first time that this effect may be use to design refractive index sensor of medium. Using the example of air as an environment, we have shown that the sensitivity of the proposed sensor concept can reach from 10-6 to 10-8, depending on the accuracy of the sphere size parameter, which is no worse than the accuracy of modern interference methods.

physics.optics

Enhanced optical trapping assisted by resonant energy backflow in a perforated dielectric microsphere

Optical energy flow inside a dielectric microsphere exposed to an optical wave is usually codirected with its wave vector. At the same time, if the optical field in a microparticle is in resonance with a high-quality spatial eigenmode, referred to as the whispering-gallery mode (WGM), at least two regions of reverse energy flow emerge in the illuminated and shadow particle hemispheres. These areas are of considerable practical interest due to their enhanced optical trapping potential provided they should be previously cleared from particle material. In this paper, we consider a perforated microsphere with an air-filled pinhole fabricated along the particle diameter and theoretically analyze the conditions for WGMs excitation. A pinhole isolates the energy backflow regions of WGM and multiple enhances the optical pull-in force that transforms a perforated microsphere into an efficient optical tweezer for trapping various nanoobjects.

physics.optics

Magnetic hot-spots generation at optical frequencies in all-dielectric mesoscale Janus particles

At optical frequencies due to the small value of the magnetic permeability of natural materials, the magnetic effects are week. To this end, the natural dielectric materials are unemployable for practical magnetic applications in optics. We have shown that it is possible to induce the intense magnetic hot spots in a Janus dielectric mesoscale particle. The basic idea of the Janus particle based on a combination of the effects of a photonic jet, whispering gallery waves and the concept of solid immersion. Simulations show that H^2/E^2 contrast maybe more 10 and maximal magnetic field intensity enhancement is more than 1000 for a wavelength-scaled particle with refractive index less than 2.

physics.optics

Subwavelength field localization based on dielectric mesoscale particle with single and blind nanohole array

Some new unusual physical phenomena and effects associated with dielectric mesoscale particles with Mie size parameter near 10 were studied and have been discovered during the last decade. In this paper, we propose nanoholes structured wavelength-scaled dielectric cubic particle with refractive index near two, where the array of nanoholes can act as a plurality of near-field probes to simultaneously illuminate the sample surface and it has the potential of surpassing the performance of most existing nearfield imaging approaches. We also offer the concept of the single nano-structuring of a dielectric cylinder or sphere made from conventional optical materials. The choice of the diameter of the nanohole in the particle "transfers" it into the resonance mode, when the characteristics of the field localized in the shadow part of the particle are determined not by the wavelength, but by the size of the nanohole. Thus, the diameter of the focused spot at the exit from the particle can be much smaller than the solid immersion diffraction limit.

physics.optics

Whispering-gallery modes promote enhanced optical backflow in a perforated dielectric microsphere

Optical energy flow inside a dielectric microsphere is usually codirected with the optical wavevector. At the same time, if the optical field in a microsphere is in resonance with one of the high-quality spatial eigenmodes (whispering-gallery modes - WGMs), a region of reverse energy flow emerges in the shadow hemisphere. This area is of considerable practical interest due to increased optical trapping potential. In this Letter, we consider a perforated microsphere with an air-filled single pinhole fabricated along the particle diameter and numerically analyze the peculiarities of WGM excitation in a nanostructured microsphere. A pinhole isolates the energy backflow region of a resonant mode and changes a perforated microsphere into an efficient optical tweezer. For the first time to our knowledge, we reveal the multiple enhancement of backflow intensity in the pinhole at a WGM resonance and discuss the way for its manipulation.

physics.optics

In-plane subwavelength near field optical capsule for lab-on-a-chip optical nano-tweezer

In this letter, we propose a new proof-of-concept of optical nano-tweezer on the basis of a pair of dielectric rectangular rods capable of generating a novel class of controlled finite-volume near field light capsules. The finite-difference time-domain simulations of light spatial structure and optical trapping forces of the gold nanoparticle immersed in water demonstrate the physical concept of an in-plane subwavelength optical capsule, integrated with the microfluidic mesoscale device. It is shown that refractive index and distance between dielectric rectangular rods can control the shape and axial position of the optical capsule. Such an in-plane wavelength-scaled structure provides a new path for manipulating absorbing nano-particles including bio-particles in a compact planar architecture and should thus open promising perspectives in lab-on-a-chip domains.

physics.optics

Near-field light-bending photonic switch: physics of switching based on three-dimensional Poynting vector analysis

Photonic hook is a high-intensity bent light focus with a proportional curvature to the wavelength of the incident light. Based on this unique light-bending phenomenon, a novel near-field photonic switch by means of a right-trapezoid dielectric Janus particle-lens embedded in the core of a planar waveguide is proposed for switching the photonic signals at two common optical communication wavelengths 1310 nm and 1550 nm by using numerical simulations. The signals at these two wavelengths can be guided to different routes according to their oppositely bent photonic hooks to realise wavelength selective switching. The switching mechanism is analysed by an in-house developed three-dimensional (3D) Poynting vector visualisation technology. It demonstrates that the 3D distribution and number of Poynting vector vortexes produced by the particle highly affect the shapes and bending directions of the photonic hooks causing the near-field switching, and multiple independent high-magnitude areas matched by the regional Poynting vector streamlines can form these photonic hooks. The corresponding mechanism can only be represented by 3D Poynting vector distributions and is being reported for the first time.

physics.optics

Photonic Lenses with Whispering Gallery Waves at Janus Particles

We show that electric field on the plane surface of truncated sphere or cylinders (so called Janus particles) have sharp resonances versus the depth of removed segment of a sphere or cylinder. These resonances are related to the excited whispering gallery waves caused by truncation. It is a new mechanism of the field localization. Optimization of this effect for cylinders permits to reach a super resolution in the line thickness what can be used for contacting optical lithography.

physics.optics

Super-enhancement focusing of Teflon sphere

A Teflon (Polytetrafluoroethylene, PTFE) sphere can be used as a focusing lens in the applications of imaging and sensing due to its low-loss property in the terahertz (THz) band. In this paper, we analytically calculated field intensities and focusing parameters for Teflon spheres at different low-loss levels and then discovered a super-enhancement focusing effect in the spheres with particular size parameters, which can stimulate about 4000 times stronger field intensity than that for incident radiation as well as the great potential of overcoming diffraction limit despite high sensitivity to the magnitude of Teflon loss. A subsequent analysis of scattering amplitudes proved that the strong scattering of a single order mode in the internal electric or magnetic field is the main factor causing this phenomenon.

physics.optics