Article
Optics
Changhong Li, Rui Yang
Summary: This article demonstrates the perfect generation of four Fano resonances with different polarizations in the mid-infrared range. It uses a hybrid graphene-dielectric metasurface consisting of silicon with embedded graphene sheets over a CaF2 substrate. By monitoring the polarization extinction ratio of the transmitting fields, tiny differences in analyte refractive index can be easily detected. The reconfigurable characteristic of graphene allows for tuning the detecting spectrum.
Article
Optics
Hugo Uittenbosch, Oliver Kliebisch, Raoul-Amadeus Lorbeer, Peter Mahnke
Summary: We propose a modified version of a two-arm, two-color, single second harmonic generation heterodyne dispersion interferometer, which reduces the number of optical elements and employs digital in-phase and quadrature demodulation for phase shift retrieval from a single photodetector signal. The system noise and drift are analyzed by measuring the Allan deviation. The device is tested for relative atmospheric pressure measurement and achieves a deviation of less than 150 Pa with an error estimation.
Article
Physics, Applied
Cai-Xing Hu, Si-Jia Guo, Hai-Feng Zhang
Summary: In this study, a RI sensor with superconducting photonic crystal in the terahertz regime was theoretically analyzed by the transfer matrix method, presenting an asymmetric resonance cavity and coupled wave theoretical model for optimization. The proposed sensing models achieve excellent performance over 80K, with sensitivity and figure of merit reaching high values at ultra-low temperatures. The performance indicators of the optimized model are dozens of times those of traditional photonic crystal RI sensors, providing theoretical guidance for the design of high-performance low-temperature RI sensors.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Yajie Liu, He Tian, Xinyi Zhang, Mingyu Wang, Yu Hao
Summary: This paper proposes a metal-insulator-metal (MIM) waveguide structure for generating quadruple Fano resonances. The resonant wavelengths of the quadruple Fano resonances can be almost independently tuned by changing the structural parameters of the three cavities. The MIM waveguide structure demonstrates excellent refractive index sensing performance and simultaneous multisolution concentration sensing capability, promoting its applications in integrated optical sensing.
Article
Optics
Hongqiang Li, Wentao Meng, Lu Cao, Lizhen Zhang, Yang Liu, Zhilin Lin, Ruina Zhao, Zhenya Song, Feng Ren, Shanshan Zhang, Liying Chen, Jinjun Bai, Mengwei Cao, Yingjie Wang, Zhiyue Zhu, Tianxue Gao, Enbang Li, Joan Daniel Prades
Summary: This paper proposes a polymer-based optical waveguide pressure sensor that can be used for medical diagnostics and health testing. The sensor has the advantages of low cost, low Young's modulus, and high sensitivity, and characterizes the change in pressure by measuring the change in Bragg wavelength.
Article
Optics
Shu Cheng, Wenbin Hu, Hongrui Ye, Lijun Wu, Qinyou Li, Ai Zhou, Minghong Yang, Qiang Zhao, Donglai Guo
Summary: By applying PDMS on a tapered multicore fiber, the temperature sensitivity of the interferometer can be improved. Experimental results show that reducing the tapered waist diameter of the fiber can enhance temperature sensitivity, with the sensor exhibiting high sensitivity of 5-25 nm/degrees C within the temperature range of 50 degrees C down to 10 degrees C.
Article
Materials Science, Multidisciplinary
Daoye Zheng, Yao Wen, Xiaocan Xu, Yu-Sheng Lin
Summary: We propose and demonstrate a metamaterial grating sensor composed of gold nanograting on a silver thin-film and encapsulated with a PDMS microfluidic chip. The sensor is sensitive to the wavevector of incident light and exhibits angle-dependent reflection spectra, with resonance peaks showing blue-shifts when isopropyl alcohol and deionized water solutions are injected. The reflected color also changes with different solutions in the ambient light environment.
MATERIALS TODAY PHYSICS
(2023)
Article
Optics
Zhou Zheng, Zhengying Li, Qingguo Du
Summary: A multi-parameter optical refractometric sensor based on lab-in-a-fiber has been proposed and investigated. It utilizes a specific three suspended-core fiber design for liquid circulation and detection. By coating a bio-recognition layer on the surface of the channels, multiple disease markers can be detected, and their concentration can be measured by the wavelength of fiber Bragg grating in each suspended core. The sensor demonstrates high sensitivity and accuracy.
Article
Chemistry, Physical
S. Simitha, Devika Mohan, Shinto M. Francis, Ajith Ramachandran, Jesly Jacob, Vibin Ipe Thomas
Summary: A dual channel sensor based on silver nanostructures was proposed for simultaneous detection of magnetic field and temperature. By optimizing the structural parameters and channel size, the sensitivity of both temperature and magnetic field was enhanced. Additionally, the detection of a single parameter was achieved by placing materials in both channels.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Mahmoud M. A. Eid, Md. Ahasan Habib, Md. Shamim Anower, Ahmed Nabih Zaki Rashed
Summary: This study presents an extremely high sensitive and nonlinear chemical sensor based on photonic crystal fiber with circular air holes for reduced fabrication complexity. The sensor ensures maximum relative sensitivity to chemicals through simulation, achieving high sensitivity at 1.55 μm of optical signal. Additionally, negligible confinement loss and other important characteristics like numerical aperture and nonlinearity are discussed in detail for better accuracy and real life environment simulation.
MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Yong Liang, Qilong Tan, Wen Zhou, Xia Zhou, Ziang Wang, Guiyao Zhou, Xuguang Huang
Summary: A dielectric gradient metasurface composed of lossless silicon nanopillars can convert incident circularly polarized light partially and the polarization conversion efficiency varies sensitively with the refractive index of surrounding media. The proposed metasurface achieves an average sensitivity of 16.134 dB/RIU at a wavelength of 1550 nm.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Keivan Mahmoud Aghdami, Abdullah Rahnama, Erden Ertorer, Peter R. Herman
Summary: This study explores the use of ultrashort-pulsed laser filaments to create high density arrays of laser filamented holes in optical fiber, resulting in high refractive index contrast Bragg gratings for telecommunications. The technique combines point-by-point fabrication with post-chemical etching to engineer strong photonic stopbands directly inside the compact and flexible fiber, allowing for high resolution refractive index sensing.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Hongyang Shen, Chunyang Liu, Fengxiang Liu, Yaqi Jin, Banghong Guo, Zhongchao Wei, Faqiang Wang, Chunhua Tan, Xuguang Huang, Hongyun Meng
Summary: A multi-band absorber based on a hybrid metal-graphene metasurface is proposed for detecting surrounding refractive index, achieving high absorption rates and sensitivities. The structure allows for flexible adjustment of absorption peaks and can be used as a refractive index sensor.
RESULTS IN PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Zhendong Yan, Chaojun Tang, Guohua Wu, Yumei Tang, Ping Gu, Jing Chen, Zhengqi Liu, Zhong Huang
Summary: This study investigates the potential of metasurfaces based on ultra-narrow band perfect absorption in the infrared region for sensing applications, with an absorption width of only 1.74 nm. The research shows that metasurfaces composed of cross-shaped holes in a silver substrate can achieve high sensitivity and figure of merit, suggesting promising applications in label-free biosensing.
Article
Chemistry, Physical
Amrita Kamkar, Kawsar Ahmed, Mirza Sanjida Alam, Fahad Ahmed Al Zahrani
Summary: This study demonstrates considerable sensitivity response using different materials for an H-shaped SPR sensor, providing selective sensitivity response with different organic materials. The optical properties of metals used were evaluated, and silver was found to have the highest sensitivity among the various metals tested.
Article
Chemistry, Multidisciplinary
Alfred J. H. Jones, Lene Gammelgaard, Mikkel O. Sauer, Deepnarayan Biswas, Roland J. Koch, Chris Jozwiak, Eli Rotenberg, Aaron Bostwick, Kenji Watanabe, Takashi Taniguchi, Cory R. . Dean, Antti-Pekka Jauho, Peter Boggild, Thomas G. Pedersen, Bjarke S. Jessen, Soren Ulstrup
Summary: This work demonstrates the controllable induction of massive Dirac fermions in a graphene device by lithographically patterning superstructures of nanoscale holes. The band dispersion of these fermions is visualized using angle-resolved photoemission spectroscopy with nanoscale spatial resolution, showing a linear scaling of effective mass with feature sizes. Electrostatic doping enhances the effective hole mass and leads to the observation of an electronic band gap, which is strongly renormalized by carrier-induced screening. This methodology allows for the engineering of band structures of massive Dirac quasiparticles at the nanoscale.
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
Chemistry, Multidisciplinary
Ehsan Amooghorban, Martijn Wubs
Summary: The study of quantum optics in metamaterials questions the applicability of classical effective-medium theories. In general, an additional effective parameter, the effective noise-photon distribution, is indispensable for active plasmonics and some passive metamaterials to predict the preservation of quantumness of light states in the metamaterial. The dependence of the effective noise-photon distribution on polarization and propagation directions is derived for both passive and active media, illustrating the robustness of the quantum optical effective-medium theory.
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
Materials Science, Multidisciplinary
Daisuke Shima, Hiroshi Sugimoto, Artyom Assadillayev, Soren Raza, Minoru Fujii
Summary: In this study, colloidal nanoparticles of gallium phosphide (GaP) with high refractive index and low extinction coefficient in the visible range were prepared using mechanical milling and pulsed laser melting. The process resulted in spherical GaP nanoparticles with a smooth surface. The scattering spectroscopy revealed distinctive Mie resonances of dipolar and higher-order modes in the visible range, which were achieved by smoothening the surface through the pulsed laser melting process. Electron energy loss spectroscopy confirmed the presence of the magnetic dipole mode at the Mie resonances. Finally, the Purcell enhancement of fluorescence on the nanoparticle surface due to the Mie resonances was demonstrated.
ADVANCED OPTICAL MATERIALS
(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
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
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
Carlos Ortega-Taberner, Antti-Pekka Jauho, Jens Paaske
Summary: Josephson junction based on quantum dots with local gates offers convenient tunability. In this study, a Josephson junction based on a serial double quantum dot gated by phase-shifted microwave tones is analyzed. The current-phase relation of the junction is modified by the phase shift between the drives. Breaking particle-hole symmetry on the dots results in a finite average anomalous Josephson current with zero phase bias. This microwave gated weak link realizes a tunable Floquet v0 junction with maximum critical current achieved slightly off resonance with the subgap excitation energy.
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.
Article
Chemistry, Multidisciplinary
P. Elli Stamatopoulou, Sotiris Droulias, Guillermo P. Acuna, N. Asger Mortensen, Christos Tserkezis
Summary: This paper introduces and analyzes the concept of manipulating optical chirality by strongly coupling the optical modes of chiral nanostructures with excitonic transitions in molecular layers or semiconductors. By demonstrating the generation of two spectral branches that retain the object's high chirality density through strong coupling with a nearby excitonic material, the authors propose that post-fabrication manipulation of optical chirality can be achieved. These findings are further verified through simulations of circular dichroism in a realistic chiral architecture.
Article
Optics
F. A. Shuklin, C. Tserkezis, N. Asger Mortensen, C. Wolff
Summary: This study analyzes the emergence of unphysical superluminal group velocities in Su-Schrieffer-Heeger (SSH) parity-time (PT) symmetric chains and explores the origins of this behavior. The analysis reveals that material dispersion is the key factor causing the divergence of group velocities. Restoring causality resolves the issue and sets practical limits on the performance of PT-symmetric systems.
