MDPI - Publisher of Open Access Journals

12 pages, 2499 KiB

Open AccessArticle

Metal Electrodes for Filtering the Localized Fundamental Mode of a Ridge Optical Waveguide on a Thin Lithium Niobate Nanofilm

by Mikhail Parfenov, Petr Agruzov, Aleksandr Tronev, Igor Ilichev, Anna Usikova, Yurii Zadiranov and Aleksandr Shamrai

Nanomaterials 2023, 13(20), 2755; https://doi.org/10.3390/nano13202755 - 13 Oct 2023

Cited by 3 | Viewed by 2032

Abstract

An approach for filtering the fundamental mode in an integrated optical modulator with multimode waveguides based on etched thin lithium niobate nanofilms is presented. It is shown that metal electrodes can be used as a modal filter to suppress high-order modes in wide multimode ridge waveguides and, consequently, to provide their quasi-single-mode regime of operation. The influence of the gap between the electrodes and its displacement relative to the waveguide symmetry axis is analyzed for various configurations of waveguides. The conditions for quasi-single-mode light propagation with suppression of high-order modes of more than 90 dB/cm are found. The influence of fabrication errors on the efficiency of modal filtering is discussed. Efficient electro-optical modulation with an equivalent voltage-length product of 4 V∙cm has been experimentally demonstrated on integrated optical phase modulator samples fabricated using conventional contact photolithography. The proposed topological solution can be further used for the fast and cheap fabrication of TFLN modulators by conventional contact photolithography. The proposed modal filtering can also be used in other waveguide topologies and in more complex waveguide devices. Full article

(This article belongs to the Special Issue Nanophotonics: Lasers, Gratings and Localized Surface Plasmons)

► Show Figures

Figure 1

18 pages, 1725 KiB

Open AccessArticle

Centrality Selection Effect on Elliptic Flow Measurements in Relativistic Heavy-Ion Collisions at NICA Energies

by Dim Idrisov, Petr Parfenov and Arkadiy Taranenko

Particles 2023, 6(2), 497-514; https://doi.org/10.3390/particles6020028 - 26 Apr 2023

Cited by 1 | Viewed by 1821

Abstract

The elliptic flow (

v_{2}

) of produced particles is one of the important observables sensitive to the transport properties of the strongly interacting matter created in relativistic heavy-ion collisions. Detailed differential measurements of

v_{2}

are also foreseen in the future [...] Read more.

The elliptic flow (

v_{2}

v_{2}

are also foreseen in the future Multi-Purpose Detector (MPD) experiment at the Nuclotron based Ion Collider fAcility (NICA) at collision energies

\sqrt{s_{N N}}

= 4–11 GeV. Elliptic flow strongly depends on collision geometry, defined by the impact parameter b. Usually b is an input to theoretical calculations and can be deduced from experimental observables in the final state using the centrality procedure. In this work, we investigate the influence of the choice of centrality procedure on the elliptic flow measurements at NICA energies. Full article

(This article belongs to the Special Issue Selected Papers from "Physics Performance Studies at FAIR and NICA")

► Show Figures

Figure 1

13 pages, 766 KiB

Open AccessArticle

Elliptic Flow and Its Fluctuations from Transport Models for Au+Au Collisions at

s_{N N}

= 7.7 and 11.5 GeV

by Vinh Ba Luong, Dim Idrisov, Petr Parfenov and Arkadiy Taranenko

Particles 2023, 6(1), 17-29; https://doi.org/10.3390/particles6010002 - 30 Dec 2022

Cited by 3 | Viewed by 2446

Abstract

The elliptic flow

v_{2}

is one of the key observables sensitive to the transport properties of the strongly interacting matter formed in relativistic heavy-ion collisions. In this work, we report on the calculations of

v_{2}

and its fluctuations of charged hadrons [...] Read more.

The elliptic flow

v_{2}

is one of the key observables sensitive to the transport properties of the strongly interacting matter formed in relativistic heavy-ion collisions. In this work, we report on the calculations of

v_{2}

and its fluctuations of charged hadrons produced in Au+Au collisions at center-of-mass energy per nucleon pair

\sqrt{s_{N N}}

= 7.7 and 11.5 GeV from several transport models and provide a direct comparison with published results from the STAR experiment. This study motivates further experimental investigations of

v_{2}

and its fluctuations with the Multi-Purpose Detector (MPD) at the NICA Collider. Full article

(This article belongs to the Special Issue Selected Papers from "Physics Performance Studies at FAIR and NICA")

► Show Figures

Figure 1

19 pages, 1401 KiB

Open AccessArticle

Model Study of the Energy Dependence of Anisotropic Flow in Heavy-Ion Collisions at

\sqrt{s_{N N}}

= 2–4.5 GeV

by Petr Parfenov

Particles 2022, 5(4), 561-579; https://doi.org/10.3390/particles5040040 - 9 Dec 2022

Cited by 11 | Viewed by 2021

Abstract

The anisotropic flow is one of the important observables sensitive to the equation of state (EOS) and transport properties of the strongly interacting matter created in relativistic heavy-ion collisions. In this work, we report a detailed multi-differential study of the directed ( [...] Read more.

v_{1}

), elliptic (

v_{2}

), triangular (

v_{3}

), and quadrangular (

v_{4}

) flow coefficients of protons in relativistic heavy-ion collisions at

\sqrt{s_{N N}}

= 2.2–4.5 GeV using several hadronic transport models. Recent published results for Au + Au collisions at

\sqrt{s_{N N}}

= 2.4 GeV from HADES experiment and at

\sqrt{s_{N N}}

= 3.0 GeV from the STAR experiment have been used for comparison. The study motivates further experimental investigations of the anisotropic collective flow of protons and neutrons in a high baryon density region. Full article

(This article belongs to the Special Issue Selected Papers from "Physics Performance Studies at FAIR and NICA")

► Show Figures

Figure 1

13 pages, 824 KiB

Open AccessArticle

Relating Charged Particle Multiplicity to Impact Parameter in Heavy-Ion Collisions at NICA Energies

by Petr Parfenov, Dim Idrisov, Vinh Ba Luong and Arkadiy Taranenko

Particles 2021, 4(2), 275-287; https://doi.org/10.3390/particles4020024 - 4 Jun 2021

Cited by 20 | Viewed by 4505

Abstract

The size and evolution of the matter created in relativistic heavy-ion collisions strongly depend on collision geometry, defined by the impact parameter. However, the impact parameter cannot be measured directly in an experiment but might be inferred from final state observables using the centrality procedure. We present the procedure of centrality determination for the Multi-Purpose Detector (MPD) at the NICA collider and its performance using the multiplicity of produced charged particles at midrapidity. The validity of the procedure is assessed using the simulated data for Au + Au collisions at

\sqrt{s_{N N}}

= 4–11 GeV. Full article

(This article belongs to the Special Issue Analysis Techniques and Physics Performance Studies for FAIR and NICA)

► Show Figures

Figure 1

13 pages, 2175 KiB

Open AccessConference Report

Anisotropic Flow Measurements of Identified Hadrons with MPD Detector at NICA

by Petr Parfenov, Dim Idrisov, Vinh Ba Luong, Nikolay Geraksiev, Anton Truttse and Alexander Demanov

Particles 2021, 4(2), 146-158; https://doi.org/10.3390/particles4020014 - 27 Mar 2021

Cited by 2 | Viewed by 3036

Abstract

The primary scientific mission of the Multi-Purpose Detector (MPD) at the accelerator Nuclotron-based Ion Collider facility (NICA) (Dubna) is to investigate the properties of strongly interacting matter at high net-baryon densities. The goal of this work is to study the performance of the MPD detector for directed and elliptic flow measurements of identified hadrons by using the realistic Monte Carlo simulations of heavy-ion collisions at energies

\sqrt{s_{N N}}

= 4.5 − 11 GeV. Full article

(This article belongs to the Special Issue Analysis Techniques and Physics Performance Studies for FAIR and NICA)

► Show Figures

Figure 1

11 pages, 1874 KiB

Open AccessArticle

Optical Properties, Morphology, and Stability of Iodide-Passivated Lead Sulfide Quantum Dots

by Ivan D. Skurlov, Iurii G. Korzhenevskii, Anastasiia S. Mudrak, Aliaksei Dubavik, Sergei A. Cherevkov, Petr S. Parfenov, Xiaoyu Zhang, Anatoly V. Fedorov, Aleksandr P. Litvin and Alexander V. Baranov

Materials 2019, 12(19), 3219; https://doi.org/10.3390/ma12193219 - 1 Oct 2019

Cited by 14 | Viewed by 4389

Abstract

Iodide atomic surface passivation of lead chalcogenides has spawned a race in efficiency of quantum dot (QD)-based optoelectronic devices. Further development of QD applications requires a deeper understanding of the passivation mechanisms. In the first part of the current study, we compare optics and electrophysical properties of lead sulfide (PbS) QDs with iodine ligands, obtained from different iodine sources. Methylammonium iodide (MAI), lead iodide (PbI₂), and tetrabutylammonium iodide (TBAI) were used as iodine precursors. Using ultraviolet photoelectron spectroscopy, we show that different iodide sources change the QD HOMO/LUMO levels, allowing their fine tuning. AFM measurements suggest that colloidally-passivated QDs result in formation of more uniform thin films in one-step deposition. The second part of this paper is devoted to the PbS QDs with colloidally-exchanged shells (i.e., made from MAI and PbI₂). We especially focus on QD optical properties and their stability during storage in ambient conditions. Colloidal lead iodide treatment is found to reduce the QD film resistivity and improve photoluminescence quantum yield (PLQY). At the same time stability of such QDs is reduced. MAI-treated QDs are found to be more stable in the ambient conditions but tend to agglomerate, which leads to undesirable changes in their optics. Full article

(This article belongs to the Special Issue Optical Characterization of Novel Composite and Optically Active Materials)

► Show Figures

Figure 1

Search Results (7)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (7)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI