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Theory of nonlinear terahertz susceptibility in ferroelectrics

Physical Review B 2024年第5期110卷 054311-054311页

作者： Yujie Zhu Taorui Chen Aiden Ross Bo Wang Xiangwei Guo Venkatraman Gopalan Long-Qing Chen Jia-Mian Hu Department of Materials Science and Engineering Materials Science Division

An analytical theory is developed for predicting the nonlinear susceptibility of ionic polarization to continuous electromagnetic waves in both bulk and strained thin film ferroelectrics. Using a perturbation method for solving the nonlinear equation of motion for ionic polarization within the framework of Landau-Ginzburg-Devonshire theory, the full second-order nonlinear susceptibility tensor is derived as a function of frequency, temperature, and strain. The theory predicts the coexistence of a significantly enhanced second-order dielectric susceptibility and a relatively low dielectric loss in BaTiO3 films with a strain-stabilized monoclinic ferroelectric phase and in a strained SrTiO3 film near its temperature-driven second-order ferroelectric-to-paraelectric phase transition. In this paper, we establish a theoretical framework for predicting and exploiting nonlinear interactions between terahertz waves and ferroelectric materials and, more generally, suggest exciting opportunities to strain-engineer nonlinear dynamical properties of ferroelectrics beyond the static and quasistatic limits.

关键词： Ferroelectricity Ferroelectrics Classical electromagnetism Electromagnetic wave theory finite-difference time-domain method Landau-Ginzburg-Devonshire theory Phase-field modeling

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Phase-change nonlocal metasurfaces for dynamic wave-front manipulation

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Physical Review Applied 2024年第4期21卷 044004-044004页

作者： Tingting Liu Dandan Zhang Wenxing Liu Tianbao Yu Feng Wu Shuyuan Xiao Lujun Huang Andrey E. Miroshnichenko Institute for Advanced Study Nanchang University Nanchang 330031 China School of Physics and Materials Science Nanchang University Nanchang 330031 China School of Optoelectronic Engineering Guangdong Polytechnic Normal University Guangzhou 510665 China School of Physics and Electronic Sciences East China Normal University Shanghai 200241 China School of Engineering and Technology University of New South Wales Canberra ACT 2612 Australia

Recent advances in nonlocal metasurfaces have enabled unprecedented success in shaping the wave front of light with spectral selectivity, offering alternative solutions for many emerging nanophotonics applications. The ability to tune both the spectral and spatial properties of such a class of metasurfaces is highly desirable, but the dynamic nonvolatile control remains elusive. Here, we demonstrate active narrowband wave-front manipulation by harnessing quasi-bound states in the continuum (quasi-BICs) in phase-change nonlocal metasurfaces. The proof-of-principle metasurfaces made of Sb2S3 allow for nonvolatile, reversible, and tunable spectral control over wave front and switchable spatial response at a given wavelength in the near-infrared regime. The design principle mainly builds upon the combination of the geometry phase of quasi-BICs and the dynamic tunability of phase-change meta-atoms to tailor the spatial response of light at tunable resonant wavelengths. By tuning the crystallization level of Sb2S3 meta-atoms through controlling the external stimuli, the dynamic nonlocal wave-front-shaping functionalities of beam steering, one-dimensional, and two-dimensional focusing, and holographic imaging are achieved exclusively at resonant wavelengths, with functionally transparent off resonance. This work represents a critical advance towards developing an integrated dynamic nonlocal metasurface for future augmented and virtual reality wearables.

关键词： Bound states in the continuum Nanophotonics Nonlocality Phase-change materials Chalcogenides Metasurfaces Optical materials & elements finite-difference time-domain method

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Nano-diffractive elements in BSI Pixel CMOS Image Sensors: Optical Design and Process Integration co-optimization with pixel Scaling 26

Nano-diffractive elements in BSI Pixel CMOS Image Sensors: O...

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Conference on Integrated Optics - Devices, Materials, and Technologies XXVI at SPIE OPTO Conference

作者： Barlas, M. Crocherie, A. Bardonnet, F. Abadie, Q. Sungauer, E. Vignetti, M. Mamdy, B. Nicholson, I D'Aillon, P. G. Bianchi, A. R. Mugny, G. Golanski, D. Domengie, F. Besson, P. Prevost, E. Parmigianni, L. Arnaud, J. Wehbe-Alause, H. Tournier, A. Noblanc, O. Rochereau, K. STMicroelectronics 850 Rue Jean Monnet F-38920 Crolles France CEA Leti 17 Ave Martyrs F-38054 Grenoble France

ISBN: (纸本)9781510648807;9781510648791

Next-generation BSI CMOS Imager Sensors are strongly driven by novel applications in depth sensing, mainly operating in the NIR (940nm) spectrum. As a result, the need for higher pixel sensitivity while shrinking pixel pitch is more present than ever. In this work, we present a new technology platform based on ad-hoc nano diffractor geometries, integrated in the Back Side of BSI CIS that allow to drastically improve the QE of the sensor for pitches varying from 10 mu m down to 2.2 mu m, co-optimized for both optical and electronic pixel performance

关键词： Quantum efficiency Silicon Photodiodes finite-difference time-domain method Optical design Near infrared Image sensors Infrared sensors Optoelectronics integration Very large scale integration

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Single-photon generation through cavity-STIRAP in a neutral QD embedded in a micropillar cavity: an FDTD model study

Single-photon generation through cavity-STIRAP in a neutral ...

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Photonics for Quantum Conference

作者： Slavcheva, Gaby M. Koleva, Mirella Mueller, Kai Taylor, Robert Quantopticon Ltd 13 Broomfield Guildford GU2 8LQ Surrey England Tech Univ Munich Walter Schottky Inst Coulombwall 4 D-85748 Garching Germany Tech Univ Munich Phys Dept Coulombwall 4 D-85748 Garching Germany Univ Oxford Dept Phys Clarendon Lab Oxford OX1 3PU England

ISBN: (纸本)9781510654761;9781510654754

We investigate cavity-assisted Stimulated Raman Adiabatic passage (STIRAP) schemes in semiconductor quantum dots (QDs) embedded in an optical cavity as a route for generation of high-quality single photons with programmable waveform. This work addresses the need for high-purity, indistinguishable photons in linear quantum computing, boson sampling, and quantum communications. We develop a time-dependent Maxwell-pseudospin model of single-photon generation through cavity-assisted adiabatic passage in a.-system isolated in a neutral InAs QD in a realistic GaAs/AlGaAs micropillar cavity. As a model.-system, we consider QD biexciton triplet states coupled to dark-exciton states by a circularly polarised pulse and a cavity field. Our simulations demonstrate control of the emitted single-photon pulse waveform by the driving pulse characteristics: shape, duration, intensity and detuning.

关键词： cavity-QED single photons STIRAP semiconductor quantum dots micropillar cavities Maxwellpseudospin equations finite-difference time-domain method

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Layer Number-Dependent Enhanced Photoluminescence from a Quantum Dot Metamaterial Optical Resonator

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ACS APPLIED ELECTRONIC MATERIALS 2021年第1期3卷 468-475页

作者： Takekuma, Haruka Leng, Junfu Tateishi, Kazutaka Xu, Yang Chan, Yinthai Ryuzaki, Sou Wang, Pangpang Okamoto, Koichi Tamada, Kaoru Kyushu Univ Inst Mat Chem & Engn IMCE Fukuoka 8190395 Japan ASTAR Inst Mat Res & Engn IMRE Singapore 138634 Singapore Natl Univ Singapore NUS Dept Chem Singapore 117543 Singapore Fukuoka Ind Acad Symphonic FiaS Inst Syst Informat Technol & Nanotechnol ISIT Nanomat Grp Fukuoka 8190388 Japan Osaka Prefecture Univ Dept Phys & Elect Sakai Osaka 5998531 Japan Tohoku Univ Adv Inst Mat Res AIMR Sendai Miyagi 9808577 Japan

High-density colloidal quantum dot (QD) thin films are promising materials for optoelectronic devices. Our experimental data revealed a unique layer number-dependent photo- luminescence (PL) from multilayered QDs on a gold substrate. Compared with the PL intensity of QDs on glass substrates, the PL intensity of CdSe/ZnS QD multilayers on the gold substrate was enhanced approximately 10-fold with 6 layers (film thickness: 42 nm). This phenomenon was simply and reasonably explained by an optical simulation using the finite-difference time-domain method with the effective medium approximation, where the light confinement effect of the high-refractive index QD film acting as a "metamaterial optical resonator" was considered together with a long-range exciton-surface plasmon coupling and mirror effects. This result explains the QD film properties from both quantum physics and optical metamaterial viewpoints. This finding is important for the design of high-luminescence thin-film displays composed of condensed QD films.

关键词： quantum dots self-assembly exciton-surface plasmon coupling photoluminescence metamaterial finite-difference time-domain method

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Distance-Dependent Plasmon-Enhanced Fluorescence of Submonolayer Rhodamine 6G by Gold Nanoparticles

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NANOSCALE RESEARCH LETTERS 2021年第1期16卷 1-7页

作者： Bian, Yajie Liu, Shikang Zhang, Yuyi Liu, Yiting Yang, Xiaoyu Lou, Shitao Wu, E. Wu, Botao Zhang, Xiaolei Jin, Qingyuan East China Normal Univ State Key Lab Precis Spect Shanghai 200241 Peoples R China Shanxi Univ Collaborat Innovat Ctr Extreme Opt Taiyuan 030006 Shanxi Peoples R China

We investigate the fluorescence from submonolayer rhodamine 6G molecules near gold nanoparticles (NPs) at a well-controlled poly (methyl methacrylate) (PMMA) interval thickness from 1.5 to 21 nm. The plasmonic resonance peaks of gold NPs are tuned from 530 to 580 nm by the PMMA spacer of different thicknesses. Then, due to the plasmonic resonant excitation enhancement, the emission intensity of rhodamine 6G molecules at 562 nm is found to be enhanced and shows a decline as the PMMA spacer thickness increases. The variation of spectral intensity simulated by finite-difference time-domain method is consistent with the experimental results. Moreover, the lifetime results show the combined effects to rhodamine 6G fluorescence, which include the quenching effect, the barrier effect of PMMA as spacer layer and the attenuation effect of PMMA films.

关键词： Rhodamine 6G molecule Gold nanoparticles Poly (methyl methacrylate) Photoluminescence Plasmon-enhanced fluorescence Quenching effect Atomic force microscope Scanning tunneling microscope finite-difference time-domain method

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Sub-50-pm displacement sensing via phase-matched metasurface-prism configuration

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Optics letters 2025年第12期50卷 3919-3922页

作者： Zhouxin Liang Xin Gu Jiaqi Li Lixun Wu Zhaoxiang Zhu Shuqing Lin Yuhang Lin Yujie Chen Siyuan Yu State Key Laboratory of Optoelectronic Materials and Technologies Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems School of Electronics and Information Technology Sun Yat-sen University Guangzhou 510275 China

Accurate transverse displacement measurement at the picometer scale is essential for advancing ultraprecision metrology and probing microscopic physical interactions. Here, we demonstrate a high-precision transverse displacement sensor leveraging a phase-matched Pancharatnam-Berry (PB) metasurface and trapezoidal prism configuration, which simplifies optical alignment by eliminating stringent Talbot self-imaging requirements. By synergistically matching the phase gradient of the PB metasurface with the prism geometry, we enable robust signal extraction through the photonic spin Hall effect, while a near-infrared source ( = 1550 nm) suppresses environmental interference. Differential amplification further rejects common-mode noise from laser fluctuations and electronic drift. The system achieves a displacement resolution of 46.18 pm under quasi-static conditions (0.2-100 Hz) and 124.86 pm across the full operational bandwidth (0.2-1.25 MHz), surpassing conventional polarization-encoded schemes in both sensitivity and practicality. This work thus presents a strategy for metasurface-enhanced metrology via geometric-phase-engineered photonic architectures, with transformative potential across applications from semiconductor lithography to quantum optomechanics.

关键词： Chemical vapor deposition finite-difference time-domain method Lithography Near infrared Optical testing Phase matching

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Broadband type-I hyperbolicity independent of carrier density in RuOCl2 crystals

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Physical Review B 2024年第11期109卷 115432-115432页

作者： Han Gao Xuejin Zhang Mingzheng Wang Chao Ding Ning Qu Bo Yang Mingwen Zhao School of Science Shandong Jianzhu University Jinan 250100 China School of Physics Shandong University Jinan 250100 Shandong China

The design and fabrication of hyperbolic metamaterials require precise control over the arrangement and dimensions of constituent components, such as nanosheets or nanowires, to achieve the desired hyperbolic dispersion. However, the ongoing challenge lies in further downsizing these components to broaden the hyperbolic regime and enhance the maximal wave vector. In this study, we propose a linear quasi-one-dimensional electron gas array model as a promising category of type-I natural hyperbolic materials (NHMs). The hyperbolic properties in these NHMs remain insensitive to the position of the Fermi level, owing to the linear dispersion relation near the Fermi level. Through first-principles calculations, we have identified a highly promising candidate material, the RuOCl2 crystal, for this model. Our research demonstrates that the RuOCl2 crystal exhibits a broad type-I hyperbolic region that spans from the infrared to the entire visible spectrum, and this property is nearly independent of the Fermi level's position, or equivalently, the carrier density. We also investigate the exceptional negative refraction effects and directional-propagating surface plasmon polaritons that arises from the hyperbolic equifrequency contour. These findings offer a universal approach to designing type-I NHMs, as well as a compelling foundation for development of cutting-edge optoelectronic devices.

关键词： Electronic structure Plasmons Layered crystals Density functional theory finite-difference time-domain method

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Space-time metallic metasurfaces for frequency conversion and beamforming

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Physical Review Applied 2024年第6期21卷 064018-064018页

作者： Salvador Moreno-Rodríguez Antonio Alex-Amor Pablo Padilla Juan F. Valenzuela-Valdés Carlos Molero Department of Signal Theory Telematics and Communications Research Centre for Information and Communication Technologies (CITIC-UGR) Department of Electrical and Systems Engineering

This paper details a class of metal-based space-time metasurfaces for application in wireless communications scenarios. Concretely, we describe space-time metasurfaces that periodically alternate their properties in time between three spatial states: “air,” “conductor,” and “grating.” We analyze the physics of these metastructures via a computationally efficient analytical technique based on the use of Floquet-Bloch series, integral equations, and circuit models. By doing so, we reveal features of these spatiotemporal metasurfaces: scattering parameters, field profiles, diffraction angles, and the nature of the space-time harmonics. The results, corroborated with a self-implemented numerical finite-difference time-domain approach, show the potential application of these space-time metasurfaces as beamformers acting in reflection, in transmission or both. The amplitude and direction of the diffracted orders can be electronically controlled with the parameters of the metasurface. Moreover, the intrinsic ability of time-modulated diffractive metasurfaces to mix and multiply frequencies is tested. We show how two different modulations can lead to the same diffraction angle but with different mixed output frequencies.

关键词： Beam control Frequency conversion Optoelectronics Wave scattering Metagratings Metasurfaces Wireless communication networks finite-difference time-domain method

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Microwave hinge states in a simple cubic lattice photonic crystal insulator

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Physical Review B 2024年第12期109卷 125304-125304页

作者： Shun Takahashi Yuya Ashida Huyen Thanh Phan Kenichi Yamashita Tetsuya Ueda Katsunori Wakabayashi Satoshi Iwamoto Kyoto Institute of Technology Matsugasaki Sakyo-ku Kyoto 606-8585 Japan School of Engineering Kwansei Gakuin University Sanda Hyogo 669-1330 Japan Research Center for Advanced Science and Technology The University of Tokyo 4-6-1 Komaba Meguro-ku Tokyo 153-8505 Japan Institute of Industrial Science The University of Tokyo 4-6-1 Komaba Meguro-ku Tokyo 153-8505 Japan

We numerically and experimentally demonstrated a higher-order topological state in a three-dimensional (3D) photonic crystal (PhC) with a complete photonic band gap. Two types of cubic lattices were designed with different topological invariants, which were theoretically and numerically confirmed by the finite difference of their Zak phases. Topological boundary states in the two-dimensional interfaces and hinge states in the one-dimensional corners were formed according to the higher order of bulk-boundary correspondence. Microwave measurements of the fabricated 3D PhC containing two boundaries and one corner showed a localized intensity, which confirmed the boundary and hinge states.

关键词： Photonic crystals Topological effects in photonic systems Band structure methods finite-difference time-domain method

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