arXiv subjects

Denis Kislov

Publications and source records attributed to Denis Kislov.

6 recordsLinked to original sources

arXiv2025

Direct observation of photonic spin Hall effect in Mie scattering

The photonic spin Hall effect (PSHE), a hallmark of spin-orbit interaction of light, has long been considered a promising route toward spin-controlled functionalities in nanophotonics. Yet, its practical realization has been severely limited by the inherently weak spin-orbit coupling in typical systems, resulting in vanishingly small transverse shifts and extremely low scattering efficiency. This fundamental trade-off has rendered the PSHE observable only through complex weak measurement protocols and signal amplification-approaches that come at the cost of further intensity loss, particularly in nanoscale systems. In this work, we overcome this longstanding challenge by introducing a novel mechanism based on symmetry breaking and mode coupling in a standalone scatterer, which unlocks a regime of Friedrich-Wintgen superscattering with strong near-field spin-orbit interaction. This allows for simultaneous enhancement of both the photonic spin Hall shift and the far-field scattering intensity-boosting the latter by nearly two orders of magnitude compared to conventional dipolar particles. Through tailored multipolar interference, the PSHE is made accessible at experimentally convenient angles, enabling post selection-free detection. We report the first direct experimental observation of the PSHE from a single superscattering particle, achieved in the microwave regime via polarization-resolved far-field measurements. Our findings not only validate a new physical pathway for enhancing spin-dependent light-matter interactions, but also establish a robust, scalable platform for spin-based photonic technologies. This breakthrough opens new avenues in precision optical metrology, advanced imaging, LIDAR systems, and integrated photonic circuitry, bridging a critical gap between fundamental spin optics and real-world applications.

physics.optics↗

arXiv2023

Optothermal needle-free injection of vaterite nanocapsules

The propulsion and acceleration of nanoparticles with light have both fundamental and applied significance across many disciplines. Needle-free injection of biomedical nano cargoes into living tissues is among the examples. Here we explore a new physical mechanism of laser-induced particle acceleration, based on abnormal optothermal expansion of mesoporous vaterite cargoes. Vaterite nanoparticles, a metastable form of calcium carbonate, were placed on a substrate, underneath a target phantom, and accelerated towards it with the aid of a short femtosecond laser pulse. Light absorption followed by picosecond-scale thermal expansion was shown to elevate the particles center of mass thus causing acceleration. It was shown that a 2um size vaterite particle, being illuminated with 0.5 W average power 100 fsec IR laser, is capable to overcome van der Waals attraction and acquire 15m/sec velocity. The demonstrated optothermal laser-driven needle-free injection into a phantom layer promotes the further development of light-responsive nanocapsules, which can be equipped with additional optical and biomedical functions for delivery, monitoring, and controllable biomedical dosage to name a few.

physics.optics↗

arXiv2022

Nonlinearity-induced optical torque

Optically-induced mechanical torque leading to the rotation of small objects requires the presence of absorption or breaking cylindrical symmetry of a scatterer. A spherical non-absorbing particle cannot rotate due to the conservation of the angular momentum of light upon scattering. Here, we suggest a novel physical mechanism for the angular momentum transfer to non-absorbing particles via nonlinear light scattering. The breaking of symmetry occurs at the microscopic level manifested in nonlinear negative optical torque due to the excitation of resonant states at the harmonic frequency with higher projection of angular momentum. The proposed physical mechanism can be verified with resonant dielectric nanostructures, and we suggest some specific realizations.

physics.optics↗

arXiv2019

Nanovortex-driven all-dielectric optical diffusion boosting and sorting concept for lab-on-a-chip platforms

The ever-growing field of microfluidics requires precise and flexible control over fluid flow at the micro- and nanoscales. Current constraints demand a variety of controllable components for performing different operations inside closed microchambers and microreactors. In this context, novel nanophotonic approaches can significantly enhance existing capabilities and provide new functionalities via finely tuned light-matter interaction mechanisms. Here we propose a novel design, featuring a dual functionality on-chip: boosted optically-driven particle diffusion and nanoparticle sorting. Our methodology is based on a specially designed high-index dielectric nanoantenna, which strongly enhances spin-orbit angular momentum transfer from an incident laser beam to the scattered field. As a result, exceptionally compact, subwavelength optical nanovortices are formed and drive spiral motion of peculiar plasmonic nanoparticles via the efficient interplay between curled spin optical forces and radiation pressure. The nanovortex size is an order of magnitude smaller than that provided by conventional beam-based approaches. The nanoparticles mediate nano-confined fluid motion enabling nanomixing without a need of moving bulk elements inside a microchamber. Moreover, precise sorting of gold nanoparticles, demanded for on-chip separation and filtering, can be achieved by exploiting the non-trivial dependence of the curled optical forces on the nanoobject size. Altogether, this study introduces a versatile platform for further miniaturization of moving-part-free, optically driven microfluidic chips for fast chemical synthesis and analysis, preparation of emulsions, or generation of chemical gradients with light-controlled navigation of nanoparticles, viruses or biomolecules.

physics.optics↗

arXiv2019

Diffusion-inspired time-varying phosphorescent decay in nanostructured environment

Structured environment controls dynamics of light-matter interaction processes via modified local density of electromagnetic states. In typical scenarios, where nanosecond-scale fluorescent processes are involved, mechanical conformational changes of the environment during the interaction processes can be safely neglected. However, slow decaying phosphorescent complexes (e.g. lanthanides) can efficiently sense micro- and millisecond scale motion via near-field interactions. As the result, lifetime statistics can inherit information about nano-scale mechanical motion. Here we study light-matter interaction dynamics of phosphorescent dyes, diffusing in a proximity of a plasmonic nanoantenna. The interplay between the time-varying Purcell enhancement and stochastic motion of molecules is considered via a modified diffusion equation, and collective decay phenomena is analysed. Fluid properties, such as local temperature and diffusion coefficient are mapped on phosphorescent lifetime distribution extracted with the help of inverse Laplace transform. We present rather simple photonic platform enabling contactless all-optical thermometry and diffusion measurement and paving a way for a plethora of possible applications. Among them, the proposed analysis can be used for detailed studies of nanofluidic processes in lab-on-a-chip devices, which are extremely hard or even impossible to analyse with other optical methods.

physics.optics↗

arXiv2019

A novel all-dielectric optical micromixing device for lab-on-a-chip platforms

The exciting properties of high index dielectric nanoparticles exhibiting both electric and magnetic Mie resonances are nowadays paving the way towards efficient light manipulation at the nanoscale. A commonly disregarded peculiarity of light scattering by Mie particles is their ability to extract angular momentum from the incident electromagnetic field. In this work, we have investigated numerically and analytically the angular momentum transfer from a circularly polarized plane wave to the transversely scattered field generated by a high index cube. Therefore, the tangential components of the Poynting vector enable predominant scattering forces in the near-field and induce orbital motion of absorbing nanoparticles in the vicinity of the scatterer. We then illustrate how these scattering forces can be utilized to realize a simple all-dielectric micromixing scheme for small dipolar spherical Au nanoparticles in an aqueous medium, accounting for the presence of Brownian and drag forces. The novel method we propose represents a step forward towards the practical implementation of efficient, all-dielectric, moving-part free, active mixing devices for a variety of microfluidics applications such as, e.g., lab-on-a-chip platforms for fast chemical synthesis and analysis, preparation of emulsions, or generation of chemical gradients.

physics.optics↗