arXiv subjects

Aleksandr Vaskin

Publications and source records attributed to Aleksandr Vaskin.

4 recordsLinked to original sources

arXiv2026

Spatio-spectrally tailored multimode metasurface lasers in the visible range

Spectrally engineered multifrequency nanolasers are highly desirable for on-chip photonics, multiplexed biosensing, and display technologies; yet, achieving them within a single compact platform remains challenging. Here, we demonstrate multimode lasing from symmetry-broken TiO2 metasurfaces integrated with an SU8 slab waveguide containing Rhodamine 6G. By co-engineering guided-mode resonances, surface lattice resonances near Rayleigh anomalies, and quasi-bound states in the continuum, we realize complementary high-Q feedback pathways that overlap with the gain spectrum. The direction of the lasing emission is tailored through outcoupling via second-order Bragg diffraction and Rayleigh anomaly conditions, supporting both normal and oblique emission. Experiments reveal discrete lasing outputs across ~100 nm bandwidth (548-648 nm), spanning nearly the full Rhodamine 6G emission band, with thresholds as low as ~7 nJ per pulse (35.7 uJ/cm^2) and up to four concurrent lasing peaks from a single device. These results establish a metasurface-dye platform for multifrequency and angle-selective lasing, opening new opportunities for compact, multifunctional nanophotonic sources.

physics.optics↗

arXiv2025

Polarization Dependent Enhancement of Magnetic Dipolar Emission with Silicon Nanodimers

Eu(TTA)3 complexes are used as an emission source in the presence of high refractive index dielectric nanostructures. These nanostructures support Mie-type resonances that modify the local density of optical states. Specifically, the silicon dimer provides polarization-dependent electric and magnetic field enhancement in the dimer gap to modify the electric dipolar and magnetic dipolar emissions of the Eu3+ at 610 nm and 590 nm, respectively. Finite element method simulations are used to determine the optimal parameters for the sample and to demonstrate the polarization-dependent emission enhancement of dipolar emitters in the gap. A two-step electron beam lithography process is used to fabricate the hybrid nanoscopic structures, with a Eu3+ doped electron beam resist located only in the center of the dimer. The results demonstrate the potential of these nanostructures to selectively tailor the emission of the two distinct dipolar transitions by engineering the resonant nanostructures. Our work highlights the potential of magnetic light-matter interactions as a novel degree of freedom.

physics.optics↗

arXiv2025

Holographic lasing with dielectric metasurfaces

Light-emitting metasurfaces provide a compact, integrated solution for simultaneous light generation and beam shaping, making them a promising candidate for advanced photonic applications. However, existing approaches for tailoring far-field emission patterns primarily operate in the spontaneous emission regime, where low coherence limits precise light control. Here, we present a light-emitting metasurface system with holographic lasing output, composed of a binary-structured metasurface integrated with a gain medium, that enables coherent light generation and precise beam shaping of the output lasing emission. With a compact footprint, low lasing threshold, and wide field of view, our system offers an exceptional platform for generating arbitrarily-structured lasing light, with significant potential for miniaturized optical systems.

physics.optics↗

arXiv2017

An optical metamixer

A frequency mixer is a nonlinear device that combines electromagnetic waves to create waves at new frequencies. Mixers are ubiquitous components in modern radio-frequency technology and are widely used in microwave signal processing. The development of versatile frequency mixers for optical frequencies remains challenging: such devices generally rely on weak nonlinear optical processes and, thus, must satisfy phase matching conditions. In this work, we utilize a GaAs-based dielectric metasurface to demonstrate an optical frequency mixer that concurrently generates eleven new frequencies spanning the ultraviolet to near-infrared (NIR) spectral range. Our approach combines strong intrinsic material nonlinearities, enhanced electromagnetic fields, and relaxed phase-matching requirements, to allow seven different nonlinear optical processes to occur simultaneously. Specifically, when pumped by two femtosecond NIR pulses, we observe second-, third- and fourth-harmonic generation, sum-frequency generation, two-photon absorption induced photoluminescence, four-wave mixing, and six-wave mixing. Such ultracompact optical mixers may enable a plethora of applications in biology, chemistry, sensing, communications and quantum optics.

physics.optics↗