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Million-Q Free Space Meta-Optical Resonator at Visible Wavelengths

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arXiv 2024年

作者： Fang, Jie Chen, Rui Sharp, David Renzi, Enrico M. Manna, Arnab Kala, Abhinav Mann, Sander A. Yao, Kan Munley, Christopher Rarick, Hannah Tang, Andrew Pumulo, Sinabu Zheng, Yuebing Menon, Vinod M. Alù, Andrea Majumdar, Arka Department of Electrical and Computer Engineering University of Washington SeattleWA98195 United States Department of Physics University of Washington SeattleWA98195 United States Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center City University of New York New YorkNY10016 United States Walker Department of Mechanical Engineering Texas Materials Institute The University of Texas at Austin AustinTX78712 United States Department of Materials Science and Engineering University of Washington SeattleWA98195 United States Department of Physics City College of New York New YorkNY10031 United States

High-quality (Q)-factor optical resonators with extreme temporal coherence are of both technological and fundamental importance in optical metrology1,2, continuous-wave lasing3-5, and semiconductor quantum optics6-8. Despite extensive efforts in designing high-Q resonators across different spectral regimes, the experimental realization of very large Q-factors at visible wavelengths remains challenging due to the small feature size that is sensitive to fabrication imperfections9-12, and thus is typically implemented in integrated photonics1-4,9,10. In the pursuit of free-space optics with the benefits of large space-bandwidth product and massive parallel operations13,14, here we design and fabricate a visible-wavelength etch-free metasurface with minimized fabrication defects and experimentally demonstrate a million-scale ultrahigh-Q resonance. A new laser-scanning momentum-space-resolved spectroscopy technique with extremely high spectral and angular resolution is developed to characterize the record-high Qfactor as well as the dispersion of the million-Q resonance in free space. By integrating monolayer WSe2 into our ultrahigh-Q meta-resonator, we further demonstrate laser-like highly unidirectional and narrow-linewidth exciton emission, albeit without any operating power density threshold. Under continuous-wave laser pumping, we observe pump-power-dependent linewidth narrowing at room temperature, indicating the potential of our meta-optics platform in controlling coherent quantum light-sources. Our result also holds great promise for applications like optical sensing, spectral filtering, and few-photon nonlinear optics. Copyright © 2024, The Authors. All rights reserved.

关键词： Continuous wave lasers

Structural properties of hyperuniform Voronoi networks

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Physical Review E 2025年第3期111卷 034123-034123页

作者： Eli Newby Wenlong Shi Yang Jiao Reka Albert Salvatore Torquato Department of Physics Pennsylvania State University University Park Pennsylvania 16802 USA Materials Science and Engineering Arizona State University Tempe Arizona 85287 USA Department of Physics Arizona State University Tempe Arizona 85287 USA Department of Chemistry Princeton University Princeton New Jersey 08544 USA Department of Physics Princeton University Princeton New Jersey 08544 USA Princeton Institute of Materials Princeton University Princeton New Jersey 08544 USA Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA

Disordered hyperuniform many-particle systems are recently discovered exotic states of matter, characterized by the complete suppression of normalized infinite-wavelength density fluctuations, as in perfect crystals, while lacking conventional long-range order, as in liquids and glasses. In this work, we begin a program to quantify the structural properties of nonhyperuniform and hyperuniform networks. In particular, large two-dimensional (2D) Voronoi networks (graphs) containing approximately 10,000 nodes are created from a variety of different point configurations, including the antihyperuniform hyperplane intersection process (HIP), nonhyperuniform Poisson process, nonhyperuniform random sequential addition (RSA) saturated packing, and both non-stealthy and stealthy hyperuniform point processes. We carry out an extensive study of the Voronoi-cell area distribution of each of the networks by determining multiple metrics that characterize the distribution, including their average areas and corresponding variances as well as higher-order cumulants (i.e., skewness γ1 and excess kurtosis γ2). We show that the HIP distribution is far from Gaussian, as evidenced by a high skewness (γ1=3.16) and large positive excess kurtosis (γ2=16.2). The Poisson (with γ1=1.07 and γ2=1.79) and non-stealthy hyperuniform (with γ1=0.257 and γ2=0.0217) distributions are Gaussian-like distributions, since they exhibit a small but positive skewness and excess kurtosis. The RSA (with γ1=0.450 and γ2=−0.0384) and the highest stealthy hyperuniform distributions (with γ1=0.0272 and γ2=−0.0626) are also non-Gaussian because of their low skewness and negative excess kurtosis, which is diametrically opposite of the non-Gaussian behavior of the HIP. The fact that the cell-area distributions of large, finite-sized RSA and stealthy hyperuniform networks (e.g., with N≈10,000 nodes) are narrower, have larger peaks, and smaller tails than a Gaussian distribution implies that in the thermodynamic limit th

关键词： Gaussian distribution

Manipulating Fano coupling in an opto-thermoelectric field

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arXiv 2024年

作者： Lin, Linhan Lepeshov, Sergey Krasnok, Alex Huang, Yu Jiang, Taizhi Peng, Xiaolei Korgel, Brian A. Alu, Andrea Zheng, Yuebing State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Tsinghua University Beijing100084 China Department of Electrical and Photonics Engineering DTU Electro Technical University of Denmark Building 343 Kgs. LyngbyDK-2800 Denmark Department of Electrical and Computer Engineering Florida International University MiamiFL33174 United States School of Physics and Electronics Hunan University Changsha410082 China Mc Ketta Department of Chemical Engineering The University of Texas at Austin AustinTX78712 United States Materials Science & Engineering Program Texas Materials Institute The University of Texas at Austin AustinTX78712 United States Department of Electrical and Computer Engineering The University of Texas at Austin AustinTX78712 United States Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center City University of New York NY10016 United States Walker Department of Mechanical Engineering The University of Texas at Austin AustinTX78712 United States

Fano resonances in photonics arise from the coupling and interference between two resonant modes in structures with broken symmetry. They feature an uneven and narrow and tunable lineshape, and are ideally suited for optical spectroscopy. Many Fano resonance structures have been suggested in nanophotonics over the last ten years, but reconfigurability and tailored design remain challenging. Herein, we propose an all-optical "pick-and-place" approach aimed at assemble Fano metamolecules of various geometries and compositions in a reconfigurable manner. We study their coupling behavior by in-situ dark-field scattering spectroscopy. Driven by a light-directed opto-thermoelectric field, silicon nanoparticles with high quality-factor Mie resonances (discrete states) and low-loss BaTiO3 nanoparticles (continuum states) are assembled into all-dielectric heterodimers, where distinct Fano resonances are observed. The Fano parameter can be adjusted by changing the resonant frequency of the discrete states or the light polarization. We also show tunable coupling strength and multiple Fano resonances by altering the number of continuum states and discrete states in dielectric heterooligomers. Our work offers a general design rule for Fano resonance and an all-optical platform for controlling Fano coupling on demand. Copyright © 2024, The Authors. All rights reserved.

关键词： Light polarization

Effect of double-extrusion following by stepwise-hot-rolling on microstructures and mechanical properties of Mg-Gd-Y-Zn-Zr alloy

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Journal of Magnesium and Alloys 2025年

作者： Wang, Jinjun Khan, Muhammad Abubaker Dai, Shang Feng, Yun Wang, Han Afifi, Mohamed A. Li, Jingyuan Beijing Advanced Innovation Center for Materials Genome Engineering National Key Laboratory of Advanced Stainless Steel School of Materials Science and Engineering University of Science and Technology Beijing Beijing100083 China Mechanical Engineering Program School of Engineering and Applied Sciences Nile University Giza12677 Egypt Nile University Giza12677 Egypt

Mg alloys with a combination of high strength and excellent ductility are increasingly required for structural applications. This study investigates the influence of advanced processing techniques on the mechanical properties and microstructural evolution of Mg-Gd-Y-Zn-Zr alloys. Utilizing a combination of double extrusion and stepwise hot rolling followed by aging treatments, significant enhancements in the mechanical performance of these alloys are demonstrated. The processing techniques applied lead to notable refinement in grain-size and modifications in the microstructure, including the transformation of LPSO phases from 18R to 24R and the dispersion of β phase particles. These microstructural transformations contribute to a substantial increase in yield-strength, ultimate-tensile-strength, and ductility. Furthermore, findings reveal that these improvements are also supported by alterations in material texture, which influence dislocation dynamics as indicated by changes in Kernel Average Misorientation (KAM) values. The combined effect of grain boundary (GB) strengthening, phase distribution, and texture modification elucidates the observed mechanical enhancements. This research provides valuable insights into the design and optimization of Mg-Gd-Y-Zn-Zr alloys for critical applications in aerospace and automotive industries where high strength and ductility are paramount. © 2025

关键词： Tensile strength

Crimped nanofiber scaffold mimicking tendon-to-bone interface for fatty-infiltrated massive rotator cuff repair

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Bioactive materials 2022年第10期7卷 149-161页

作者： Liren Wang Tonghe Zhu Yuhao Kang Jianguang Zhang Juan Du Haihan Gao Sihao Chen Jia Jiang Jinzhong Zhao Department of Sports Medicine Department of OrthopedicsShanghai Institute of Microsurgery on ExtremitiesShanghai Jiao Tong University Affiliated Sixth People’s HospitalNo.600 Yishan RoadShanghai200233China Regenerative Sports Medicine and Translational Youth Science and Technology Innovation Workroom Shanghai Jiao Tong University School of MedicineNo.227 South Chongqing RoadShanghai200025China Department of Medgen Group Research Laboratory 18 Qinglan 3 RdShenzhen518118China Biofunctional Materials Research Group College of Chemistry and Chemical EngineeringMultidisciplinary Center for Advanced MaterialsInstitute of Advanced StudiesShanghai University of Engineering ScienceNo.333 Longteng RdShanghai201620China Shanghai Jiao Tong University School of Medicine No.227 South Chongqing RoadShanghai200025China Regenerative Sports Medicine Lab of the Institute of Microsurgery on Extremities Shanghai Jiao Tong University Affiliated Sixth People’HospitalNo.600 Yishan RoadShanghai200233China

Electrospun fibers,with proven ability to promote tissue regeneration,are widely being explored for rotator cuff ***,without post treatment,the microstructure of the electrospun scaffold is vastly different from that of natural extracellular matrix(ECM).Moreover,during mechanical loading,the nanofibers slip that hampers the proliferation and differentiation of migrating stem ***,electrospun nanofiber scaffolds,with crimped nanofibers and welded joints to biomimic the intricate natural microstructure of tendon-to-bone insertion,were prepared using poly(ester-urethane)urea and gelatin via electrospinning and double crosslinking by a multi-bonding network densification *** crimped nanofiber scaffold(CNS)features bionic tensile stress and induces chondrogenic differentiation,laying credible basis for in vivo *** repairing a rabbit massive rotator cuff tear using a CNS for 3 months,the continuous translational tendon-to-bone interface was fully regenerated,and fatty infiltration was simultaneously *** of micro-CT,μCT was employed to visualize the integrity and intricateness of the three-dimensional microstructure of the CNS-induced-healed tendon-to-bone interface at an ultra-high resolution of less than 1μ*** study sheds light on the correlation between nanofiber post treatment and massive rotator cuff repair and provides a general strategy for crimped nanofiber preparation and tendon-to-bone interface imaging characterization.

关键词： Massive rotator cuff tear Fatty infiltration Nanofiber scaffold Crimped structure Tendon-to-bone interface

An overview of high-throughput synthesis for advanced high-entropy alloys

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materials Genome engineering Advances 2025年第1期3卷

作者： Tong Xie Weidong Li Gihan Velisa Shuying Chen Fanchao Meng Peter K. Liaw Yang Tong Institute for Advanced Studies in Precision Materials Yantai University Yantai Shandong China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology Beijing Beijing China Horia Hulubei National Institute for Physics and Nuclear Engineering Bucharest Romania Department of Materials Science and Engineering University of Tennessee Knoxville Tennessee USA

High-entropy alloys (HEAs) have revolutionized alloy design by integrating multiple principal elements in equimolar or near-equimolar ratios to form solid solutions, vastly expanding the compositional space beyond traditional alloys based on a primary element. However, the immense compositional complexity presents significant challenges in designing alloys with targeted properties, as billions of new alloy systems emerge. High-throughput approaches, which allow the parallel execution of numerous experiments, are essential for accelerated HEA design to navigate this extensive compositional space and fully exploit their potential. Here, we reviewed how advancements in high-throughput synthesis tools have accelerated HEA database development. We also discussed the advantages and limitations of each high-throughput fabrication methodology, as understanding these is vital for achieving precise HEA design.

关键词： combinatorial thin-film synthesis diffusion multiples high-entropy alloys high-throughput directed energy deposition high-throughput synthesis

Picosecond optical-to-x-ray (Cd,Mg)Te radiation detectors

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Picosecond optical-to-x-ray (Cd,Mg)Te radiation detectors

Conference on Lasers and Electro-Optics (CLEO)

作者： J. Cheng I. Komissarov G. Chen D. Chakraborty S. Kutcher H. Chen S. Trivedi Roman Sobolewski Materials Science Graduate Program University of Rochester Rochester New York USA Laboratory for Laser Energetics University of Rochester Rochester New York USA Department of Electrical and Computer Engineering University of Rochester Rochester New York USA Brimrose Technology Corp Sparks Maryland USA

We developed a dual optical/x-ray ultrafast photodetector based on in-house grown Cd 0.97 Mg 0.03 Te single crystals. The detector is characterized by ~200 ps full-width-at-half-maximum, readout-electronics limited p... 详细信息

ISBN: (纸本)9781957171258

关键词： Femtosecond lasers Photodetectors Photon counting Pump probe spectroscopy Radiation detectors Ti:sapphire lasers

Spectroscopic and Interferometric Sum-Frequency Imaging of Strongly Coupled Phonon Polaritons in SiC Metasurfaces

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arXiv 2023年

作者： Niemann, Richarda Mueller, Niclas S. Wasserroth, Sören Lu, Guanyu Wolf, Martin Caldwell, Joshua D. Paarmann, Alexander Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6 Berlin14195 Germany Department of Mechanical Engineering Vanderbilt University NashvilleTN37235 United States Interdisciplinary Materials Science Graduate Program Vanderbilt University NashvilleTN37235 United States

Phonon polaritons enable waveguiding and localization of infrared light with extreme confinement and low losses. The spatial propagation and spectral resonances of such polaritons are usually probed with complementary techniques such as near-field optical microscopy and far-field reflection spectroscopy. Here, we introduce infrared-visible sum-frequency spectro-microscopy as a tool for spectroscopic imaging of phonon polaritons. The technique simultaneously provides sub-wavelength spatial resolution and highly-resolved spectral resonance information. This is implemented by resonantly exciting polaritons using a tunable infrared laser and wide-field microscopic detection of the upconverted light. We employ this technique to image hybridization and strong coupling of localized and propagating surface phonon polaritons in metasurfaces of SiC micropillars. Spectro-microscopy allows us to measure the polariton dispersion simultaneously in momentum space by angle-dependent resonance imaging, and in real space by polariton interferometry. Notably, we directly visualize how strong coupling affects the spatial localization of polaritons, inaccessible with conventional spectroscopic techniques. We further observe the formation of edge states at excitation frequencies where strong coupling prevents polariton propagation into the metasurface. Our approach is applicable to the wide range of polaritonic materials with broken inversion symmetry and can be used as a fast and non-perturbative tool to image polariton hybridization and propagation. © 2023, CC BY.

关键词： Polariton

Tuning light emission crossovers in atomic-scale aluminum plasmonic tunnel junctions

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arXiv 2022年

作者： Zhu, Yunxuan Cui, Longji Abbasi, Mahdiyeh Natelson, Douglas Department of Physics and Astronomy Rice University HoustonTX77005 United States Paul M. Rady Department of Mechanical Engineering University of Colorado BoulderCO80309 United States Materials Science and Engineering Program University of Colorado BoulderCO80309 United States Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Department of Materials Science and Nanoengineering Rice University HoustonTX77005 United States

Atomic sized plasmonic tunnel junctions are of fundamental interest, with great promise as the smallest on-chip light sources in various optoelectronic applications. Several mechanisms of light emission in electrically driven plasmonic tunnel junctions have been proposed, from single-electron or higher order multi-electron inelastic tunneling to recombination from a steady-state population of hot carriers. By progressively altering the tunneling conductance of an aluminum junction, we tune the dominant light emission mechanism through these possibilities for the first time, finding quantitative agreement with theory in each regime. Improved plasmonic resonances in the energy range of interest increase photon yields by two orders of magnitude. These results demonstrate that the dominant emission mechanism is set by a combination of tunneling rate, hot carrier relaxation timescales, and junction plasmonic properties. Copyright © 2022, The Authors. All rights reserved.

关键词： Tunnel junctions