Article
Chemistry, Multidisciplinary
Ufuk Kilic, Matthew Hilfiker, Alexander Ruder, Rene Feder, Eva Schubert, Mathias Schubert, Christos Argyropoulos
Summary: This article demonstrates how nanohelical metamaterials can achieve spectrally tunable, extremely large, and broadband chiroptical response, addressing the challenges in controlling and enhancing chiral light-matter interactions.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Rui Feng, Hao Wang, Yongyin Cao, Yanxia Zhang, Ray J. H. Ng, You Sin Tan, Fangkui Sun, Cheng-Wei Qiu, Joel K. W. Yang, Weiqiang Ding
Summary: The study demonstrated an all-optical continuously tunable plasmonic pixel scheme through a modular design approach to achieve polarization-controlled full color tuning.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Binghui Li, Yu-Sheng Lin
Summary: We introduce four types of tunable terahertz metamaterials made of split-ring resonators (SRRs) with different splits and inner movable structures. These designs can achieve different tuning ranges in transverse electric (TE) and transverse magnetic (TM) modes, exhibiting polarization-dependent and polarization-independent characteristics. By increasing the height of the inner movable structure, the resonant frequency of the metamaterials can be tuned. These designs possess anti-vibration and tunable characteristics, which make them potential candidates for high tunability, flexibility, and applicability in THz-wave optoelectronic devices.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Chemistry, Multidisciplinary
Tung Huu Dang, Angela Vasanelli, Yanko Todorov, Carlo Sirtori, Yoann Prado, Audrey Chu, Charlie Greboval, Adrien Khalili, Herve Cruguel, Christophe Delerue, Gregory Vincent, Emmanuel Lhuillier
Summary: The study demonstrates that bias tunable aspectral response can be achieved by coupling a HgTe NC array with a plasmonic resonator. The observed blueshift arises from the interplay between hopping transport and inhomogeneous absorption due to the presence of the photonic structure. This research expands the realm of existing NC-based devices and lays the foundation for light modulators.
Article
Chemistry, Multidisciplinary
Zachary M. Sherman, Kihoon Kim, Jiho Kang, Benjamin J. Roman, Hannah S. N. Crory, Diana L. Conrad, Stephanie A. Valenzuela, Emily Lin, Manuel N. Dominguez, Stephen L. Gibbs, Eric Anslyn, Delia J. Milliron, Thomas M. Truskett
Summary: The optical properties of nanoparticle assemblies are influenced by the unique characteristics of their building blocks and spatial organization, leading to emergent phenomena. A fast, materials agnostic method has been developed to simulate the optical response of large nanoparticle assemblies with structural and compositional complexity. This method overcomes the limitations of conventional electromagnetic simulations and achieves rapid and accurate convergence for complex configurations, enabling the design of complex and hierarchically structured assemblies with desired optical characteristics.
Article
Engineering, Electrical & Electronic
Yuanfang Yu, Mingyu Sun, Zhe Zhang, Meng Guan, Min Wang, Aixin Chen
Summary: A novel reconfigurable circularly polarized (CP) patch antenna with tunable operation band and switchable polarization states is proposed. By specially designed bias and a feed structure loaded with p-i-n diodes, the antenna achieves controllable operation band and polarization reconfigurability. The fabricated prototype shows good performance consistent with the simulation results.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2022)
Article
Physics, Multidisciplinary
Benjamin O. Asamoah, Henri Partanen, Sughra Mohamed, Janne Heikkinen, Atri Halder, Matias Koivurova, Marek Necada, Tero Setala, Jari Turunen, Ari T. Friberg, Tommi K. Hakala
Summary: In this study, the transition from spontaneous emission to stimulated emission in laser light from a plasmonic lattice overlaid with organic fluorescent molecules is investigated. The reduction of beam divergence and emission linewidth is observed as the pump fluence increases, accompanied by increased spatial and temporal coherence. The one-dimensional feedback for the lasing signal is mainly attributed to the dipolar nature of the surface lattice resonance, resulting in significant differences in beaming properties along x and y directions.
NEW JOURNAL OF PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Anton Yu. Bykov, Yuanyang Xie, Alexey V. Krasavin, Anatoly V. Zayats
Summary: In this study, the optically driven acoustic modes and nonlinear response of multilayered spherical plasmonic hetero-nanoparticles were investigated. These nanoparticles, composed of alternating layers of gold and silica, exhibited a broadband nonlinear optical response from visible to near-infrared wavelengths. Additionally, they served as a tunable optomechanical system with mechanically decoupled layers, allowing for selective switching of different acoustic modes by tuning the excitation wavelength. These findings not only enhance our understanding of the internal structure of composite plasmonic nanoparticles but also provide an additional degree of freedom for controlling their nonlinear optical and mechanical properties.
Article
Engineering, Electrical & Electronic
Min Jiang, Zelin Guo, Haonan Li, Xiaodan Liu, Feng Xu, Guanghui Wang
Summary: This letter proposes a plasmonic conveyor belt based on periodically arranged graphene nanorings (GNRs) with different sizes. By electrically tuning the Fermi level of graphene, the hot spots on the GNRs can be continuously illuminated, allowing for the trapping and transporting of nanoparticles under uniform Mid-infrared or terahertz light excitation. The rotational symmetry of the GNRs provides advantages over designs consisting of graphene strips, and the feasibility of particle separation is demonstrated. Numerical analysis confirms that this design offers an optimized scheme for polarization-independent and electrically tunable plasmonic conveyor belts, which can be used in various on-chip optofluidic applications.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yao Wen, Tao Xu, Yu-Sheng Lin
Summary: This design presents a MEMS-based tunable terahertz metamaterial device with polarization-dependent sensing characteristics. The device can achieve tunable dual-band resonances in TE and TM modes by changing the gap between resonators, and it exhibits sensitivity to changes in environmental refractive index. The results indicate high linear sensitivity and excellent performance for gas and environmental applications.
RESULTS IN PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Zhuangqiang Gao, Shikuan Shao, Weiwei Gao, Dianyong Tang, Dianping Tang, Shengli Zou, Moon J. Kim, Xiaohu Xia
Summary: The study introduces an effective method for designing morphology-stable nanoparticles with tunable plasmonic properties by controlling internal structure; Plasmonic properties of the nanoparticles can be conveniently adjusted by varying the material deposited on the inner surfaces without changing the overall morphology; The nanoparticles show potential applications in colorimetric sensing with low detection limits.
Article
Materials Science, Multidisciplinary
Yahong Zhang, Haoxu Si, Haojie Liu, Zhiyang Jiang, Anbang Li, Mengjiao Liu, Chunhong Gong
Summary: Structure design, conductivity regulation, and electromagnetic matching are crucial to optimize the electromagnetic wave absorbing properties. A heterogeneous and hierarchical Ni/C/SiO2 composite with tunable absorption properties was synthesized through a simple process. The introduction of SiO2 and Ni led to the formation of a hierarchical porous structure that extended the propagation path of EMW, realized multiple reflection and scattering, and provided sufficient interfacial polarization. Meanwhile, SiO2 and Ni nanoparticles played a key role in conductivity regulation and electromagnetic matching. The Ni/C/SiO2-0.5 exhibited the optimal absorption properties, with a maximum reflection loss of -47.65 dB at 3.1 mm with a filler content of 10 wt%. This research offers a novel strategy for the development of EMW absorbing materials.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Kang Yang, Jingyu Wang, Xu Yao, Danya Lyu, Jinfeng Zhu, Zhilin Yang, Bowen Liu, Bin Ren
Summary: The research successfully tuned the absorption efficiency and peak position of plasmonic metamaterial by adjusting the thicknesses of the hexagonal Au nanohole array and the spacer layer, achieving ultra-high absorption rate and high surface-enhanced Raman scattering effect for SERS detection with high uniformity. This work provides a simple way to flexibly adjust the optical properties of plasmonic metamaterials for various promising applications.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Computer Science, Information Systems
James T. S. Do, Jiawei Zang, Alejandro Alvarez-Melcon, Juan Sebastian Gomez-Diaz
Summary: In this paper, we propose and demonstrate time-modulated patch antennas that exhibit nonreciprocal polarization responses. The antennas use the photonic Aharonov Bohm effect to manipulate the phase of surface currents, resulting in opposite polarization ellipticity during transmission or reception. Experimental results show high conversion efficiency, isolation levels over 40 dB, and tunability to generate/receive electromagnetic waves with arbitrary polarization ellipticity.
Article
Chemistry, Physical
Mohammad Asif Zaman, Lambertus Hesselink
Summary: The plasmonic response of C-shaped nano-apertures is investigated in this study. Numerical simulations demonstrate the dependence of resonance condition on incident light wavelength and polarization. The effects of dimension scaling are also discussed. A circuit model is proposed, which relates geometrical and material parameters to equivalent circuit elements. The analysis finds correlation between the circuit model's equivalent impedance and the resonance behavior of actual C-apertures. The study's findings can be useful in designing C-apertures for various applications.
Review
Nanoscience & Nanotechnology
Sergey G. Menabde, Jacob T. Heiden, Joel D. Cox, N. Asger Mortensen, Min Seok Jang
Summary: Polaritonic modes in low-dimensional materials enable strong light-matter interactions and the manipulation of light on nanometer length scales. The recent interest in image polaritons in van der Waals crystals has gained considerable attention in nanophotonics, where a polaritonic material couples with its mirror image in close proximity to a highly conductive metal. These image modes provide an appealing nanophotonic platform with lower propagation loss and access to the nonlocal regime of light-matter interaction.
Article
Optics
Fengwen Kang, Yongping Du, Ze Yang, Philippe Boutinaud, Martijn Wubs, Jie Xu, Haiyan Ou, Dongzhe Li, Kaibo Zheng, Abebe T. Tarekegne, Guohuan Sun, Xuhui Xu, Sanshui Xiao
Summary: In this study, CsPbBr3:Ln(3+) nanocrystals grown into glass were successfully designed and fabricated using an in situ nanocrystallization method. It was found that substitution of Pb2+ sites with Ln(3+) ions led to a blueshift of emission position. The nanocrystals exhibited excellent photoluminescent properties and showed good stability in various environments. Additionally, the emission intensity could be controlled through heat-cooling experiments and laser irradiation. Furthermore, a white light-emitting prototype was achieved by combining the CsPbBr3 nanocrystals with other phosphors.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Sergii Morozov, Stefano Vezzoli, Alina Myslovska, Alessio Di Giacomo, N. Asger Mortensen, Iwan Moreels, Riccardo Sapienza
Summary: Giant shell CdSe/CdS quantum dots exhibit high brightness and flexibility, with near-unity quantum yield and suppressed blinking. However, their single photon purity is reduced due to efficient multiexcitonic emission. In this study, we observed a significant blueshift in the photoluminescence biexciton spectrum of pure-phase wurtzite quantum dots. By using spectral filtering, we achieved a 2.3 times reduction in biexciton quantum yield while preserving 60% of the exciton single photon emission, leading to an improvement in purity from g2(0)=0.07±0.01 to g2(0)=0.03±0.01. Furthermore, at higher pump fluence, the spectral purification was even more effective, resulting in up to a 6.6 times reduction in g2(0) by suppressing higher order excitons and shell states with larger blueshifts.
Article
Materials Science, Multidisciplinary
Jie Xu, Yamei Luo, Sanshui Xiao, Fengwen Kang, Kosmas L. Tsakmakidis
Summary: This study proposes an all-optical digital logical system based on unidirectional modes in the microwave regime, which can achieve continuous broadband operation for basic logic gates. Utilizing the concept of negative logic, the system exhibits low-loss, broadband, and robust characteristics, and has the potential for multi-input and/or multi-output logical functionalities, making it promising for parallel computation. The numerical simulations and theoretical analyses support the feasibility of this system.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Braulio Beltran-Pitarch, Benny Guralnik, Neetu Lamba, Andreas R. Stilling-Andersen, Lars Norregaard, Torben M. Hansen, Ole Hansen, Nini Pryds, Peter F. Nielsen, Dirch H. Petersen
Summary: In order to develop materials with higher thermoelectric efficiency, a new method based on micro four-point probe (M4PP) was developed to determine the thermal diffusivity of a bulk material using the phase delay of the second harmonic voltage. The method was tested on two relevant thermoelectric materials, skutterudite and bismuth telluride, and showed good agreement with independent estimates. The M4PP method also demonstrated the ability to characterize materials with nonuniform and erratic electrical resistivity, such as bismuth telluride.
MATERIALS TODAY PHYSICS
(2023)
Article
Optics
Arnhold Simonsen, Gyeong Cheol Park, Thor Ersted Ansbaek, Ole Hansen, Kresten Yvind
Summary: In this letter, we introduce a 2D mirror design that offers a large optical bandwidth and high reflection. This design is also more rigid than 1D mirrors. We specifically study the impact of rounded corners of rectangles during the transfer from CAD to the wafer using lithography and etching.
Article
Nanoscience & Nanotechnology
Rui Chen, Yi Zheng, Xingyu Huang, Qiaoling Lin, Chaochao Ye, Meng Xiong, Martijn Wubs, Yungui Ma, Minhao Pu, Sanshui Xiao
Summary: Obtaining bound states in the continuum (BICs) in photonic crystals allows for resonances with high quality factors for lasing and nonlinear applications. We design photonic-crystal BIC cavities encircled by the photonic bandgap of lateral heterostructures to confine the mode profile and suppress side leakage. Multiple bulk quantized modes are observed in both simulation and experiment, with resonance peaks depending on the illuminating position explained by mode profile distribution analysis and numerical simulations. Our findings have potential applications in mode selectivity for BIC devices and manipulation of lasing modes or radiation patterns in photonic-crystal surface-emitting lasers or nonlinear optics.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Alvaro Rodriguez Echarri, Fadil Iyikanat, Sergejs Boroviks, N. Asger Mortensen, Joel D. Cox, F. Javier Garcia de Abajo
Summary: The promising applications of photonics rely on the fabrication of high-quality metal thin films with controlled thickness in the range of a few nanometers. These materials exhibit highly nonlinear response to optical fields due to ultrafast electron dynamics. However, the understanding of this phenomenon on such small length scales is limited. In this study, a new mechanism controlling the nonlinear optical response of thin metallic films is revealed, which is dominated by ultrafast electronic heat transport when the film thickness is sufficiently small. By experimentally and theoretically studying electronic transport in these materials, the researchers explained the observed temporal evolution of photoluminescence in two-pulse correlation measurements. They found that ultrafast thermal dynamics plays a crucial role in determining the strength and time-dependent characteristics of the nonlinear photoluminescence signal. Their findings provide new insights into the nonlinear optical response of nanoscale materials and offer possibilities for controlling and utilizing hot carrier distributions in metallic films.
Article
Chemistry, Multidisciplinary
Yuxin Lei, Qiaoling Lin, Sanshui Xiao, Juntao Li, Hanlin Fang
Summary: This work demonstrates the generation of deep defect states in MoTe2 fewlayers via a heating process, enabling light emission in the telecommunication O-band for quantum light emission. Optical measurements reveal localized excitons and strong interaction among defects. Furthermore, the optical emission of defects depends on the thickness of the host materials. These findings offer a new route for tailoring the optical properties of two-dimensional materials in optoelectronic applications.
Article
Materials Science, Multidisciplinary
Saskia Fiedler, Sergii Morozov, Leonid Iliushyn, Sergejs Boroviks, Martin Thomaschewski, Jianfang Wang, Timothy J. Booth, Nicolas Stenger, Christian Wolff, N. Asger Mortensen
Summary: Cathodoluminescence spectroscopy combined with second-order auto-correlation measurements of g(2)(tau) allows for extensive study of the synchronization of photon emitters in low-dimensional structures. Co-existing excitons in two-dimensional transition metal dichalcogenide monolayers serve as a great source of identical photon emitters that can be simultaneously excited by an electron. In this study, we demonstrate large photon bunching with g(2)(0) up to 156 +/- 16 in a tungsten disulfide monolayer (WS2), showing a strong dependence on the electron-beam current. By carefully selecting a simple and compact geometry, such as a thin monocrystalline gold nanodisk, we achieve a record-high bunching g(2)(0) of up to 2152 +/- 236, improving the excitation synchronization and electron-emitter interaction. This approach of controlling electron excitation of excitons in a WS2 monolayer enables the synchronization of photon emitters in an ensemble, which is crucial for advancing light information and computing technologies.
Article
Chemistry, Multidisciplinary
Moritz Fischer, Ali Sajid, Jake Iles-Smith, Alexander Hoetger, Denys I. Miakota, Mark K. Svendsen, Christoph Kastl, Stela Canulescu, Sanshui Xiao, Martijn Wubs, Kristian S. Thygesen, Alexander W. Holleitner, Nicolas Stenger
Summary: By combining theory and experiments, we have identified three carbon-based defects as the microscopic origin of luminescent centers in hBN. We have also developed a method to calculate photoluminescence excitation (PLE) maps, which accurately describe the vibronic structure of the optical transition and the phonon-assisted excitation mechanism.
Article
Nanoscience & Nanotechnology
Min Zhang, Yuan Tian, Xingzhou Chen, Zheng Sun, Xiaolong Zhu, Jian Wu
Summary: This study reports the plasmon-exciton coupling in a hybrid system with a plasmonic metasurface. By finely tuning the geometric size of the plasmonic nanostructures, the dispersion relation of the coupled plasmon and exciton can be significantly modified. The experimental results show a strong coupling behavior with a achieved Rabi splitting up to 200 meV at room temperature, in ambient conditions. The effective tailoring of the plasmon-exciton coupling with the plasmonic metasurfaces provides a testing platform for studying quantum electromagnetics at the subwavelength scale and exploring plasmonic polariton Bose-Einstein condensation at room temperature.
Article
Nanoscience & Nanotechnology
Saskia Fiedler, Sergii Morozov, Danylo Komisar, Evgeny A. A. Ekimov, Liudmila F. F. Kulikova, Valery A. A. Davydov, Viatcheslav N. N. Agafonov, Shailesh Kumar, Christian Wolff, Sergey I. I. Bozhevolnyi, N. Asger Mortensen
Summary: Impurity-vacancy centers in diamond provide a class of robust photon sources with versatile quantum properties. The ensembles of color centers have tunable photon-emission statistics and their emission properties can be controlled by different types of excitation. Electron-beam excitation can synchronize the emitters' excitation and control the second-order correlation function g(2)(0), as confirmed by experimental results in this letter. Such a photon source based on an ensemble of few color centers in a diamond crystal offers a highly tunable platform for room temperature informational technologies.
Article
Optics
Christos Tserkezis, Christian Wolff, Fedor A. Shuklin, Francesco Todisco, Mikkel H. Eriksen, P. A. D. Goncalves, N. Asger Mortensen
Summary: We propose an efficient approach for actively controlling the Rabi oscillations in nanophotonic emitter-cavity analogs based on the presence of an element with optical gain. Inspired by recent developments in parity-time (PT)-symmetry photonics, we show that nano-or microcavities where intrinsic losses are partially or fully compensated by an externally controllable amount of gain offer unique capabilities for manipulating the dynamics of extended (collective) excitonic emitter systems. Furthermore, we show that there is a specific gain value that leads to an exceptional point, where both the emitter and cavity occupation oscillate practically in phase, with occupation numbers that can significantly exceed unity.
Article
Materials Science, Multidisciplinary
Gino Wegner, Dan-Nha Huynh, N. Asger Mortensen, Francesco Intravaia, Kurt Busch
Summary: The paper discusses the impact of an extended model proposed by Halevi on the nonlocal response of plasmonic materials and nanostructures. It reevaluates the Mie scattering coefficients for a cylinder and corresponding plasmon-polariton resonances within this framework. The analysis reveals a nonlocal, collisional, and size-dependent damping term that affects the resonances in the extinction spectrum. The implementation of the Halevi model in the time domain is particularly important for efficient and accurate modeling of nanogap structures and other nanoscale features in nanoplasmonics applications.