物理与天体物理最新文献

英文中文

IF： -

A Polarization-Insensitive and Adaptively-Blazed Meta-Grating Based on Dispersive Metasurfaces 基于色散元表面的偏振不敏感和自适应眩光元光栅

IF 11 1区物理与天体物理 Q1 OPTICS

Laser & Photonics Reviews

Pub Date : 2024-11-16 DOI: 10.1002/lpor.202401031

Guanxing Zang, Zhijun Liu, Shilun Feng, Weiming Zhu

The diffraction efficiency of blaze gratings is optimized only at a specific frequency due to a fixed blaze angle, resulting in reduced and variable diffraction efficiencies over the working frequency band. Additionally, blazed gratings demonstrate polarization dependence due to their groove structures and the interaction of light with their surfaces. Consequently, designing gratings with constant diffraction efficiencies across a wide frequency bandwidth while maintaining polarization independence remains a challenge. Here, a design paradigm of dispersion engineerable meta-grating inspired by orthogonal harmonic oscillations (OHO) is presented. Utilizing the OHO model, the phase dispersion of a metasurface can be precisely controlled, which applies to any unit cell featuring two orthogonal electromagnetic resonances. As a proof of concept, a polarization-insensitive meta-grating is showcased, where the blazed angle adapts with the incident frequency, ensuring broadband performance. In the experiment, the adaptively-blazed grating measured an optimized and constant diffraction efficiency of ≈80% over the working wavelength range, i.e., 8.7–12.2 µm. The difference in diffraction efficiency between the two perpendicular linear polarization states remains within 4.6%. The proposed paradigm paves the way for meta-device design based on precise dispersion engineering, which has potential applications in spectrometers, broadband beam forming and steering, hyperspectral imaging, etc.

由于光斑角度固定，光斑光栅的衍射效率只有在特定频率下才能达到最佳状态，因此在整个工作频段内衍射效率都会降低且变化不定。此外，由于其沟槽结构和光与其表面的相互作用，炽热光栅显示出偏振依赖性。因此，在设计具有宽频带恒定衍射效率的光栅时，同时保持偏振无关性仍然是一项挑战。本文介绍了一种受正交谐振（OHO）启发的可进行色散工程的元光栅设计范例。利用 OHO 模型，可以精确控制元表面的相位色散，这适用于具有两个正交电磁共振的任何单元格。作为概念验证，展示了对偏振不敏感的元光栅，其炽热角随入射频率而变化，确保了宽带性能。在实验中，自适应釉面光栅在工作波长范围（即 8.7-12.2 微米）内测得的优化恒定衍射效率≈80%。两种垂直线性偏振态之间的衍射效率差异保持在 4.6% 以内。所提出的范例为基于精确色散工程的元器件设计铺平了道路，有望应用于光谱仪、宽带波束形成和转向、高光谱成像等领域。

{"title":"A Polarization-Insensitive and Adaptively-Blazed Meta-Grating Based on Dispersive Metasurfaces","authors":"Guanxing Zang, Zhijun Liu, Shilun Feng, Weiming Zhu","doi":"10.1002/lpor.202401031","DOIUrl":"https://doi.org/10.1002/lpor.202401031","url":null,"abstract":"The diffraction efficiency of blaze gratings is optimized only at a specific frequency due to a fixed blaze angle, resulting in reduced and variable diffraction efficiencies over the working frequency band. Additionally, blazed gratings demonstrate polarization dependence due to their groove structures and the interaction of light with their surfaces. Consequently, designing gratings with constant diffraction efficiencies across a wide frequency bandwidth while maintaining polarization independence remains a challenge. Here, a design paradigm of dispersion engineerable meta-grating inspired by orthogonal harmonic oscillations (OHO) is presented. Utilizing the OHO model, the phase dispersion of a metasurface can be precisely controlled, which applies to any unit cell featuring two orthogonal electromagnetic resonances. As a proof of concept, a polarization-insensitive meta-grating is showcased, where the blazed angle adapts with the incident frequency, ensuring broadband performance. In the experiment, the adaptively-blazed grating measured an optimized and constant diffraction efficiency of ≈80% over the working wavelength range, i.e., 8.7–12.2 µm. The difference in diffraction efficiency between the two perpendicular linear polarization states remains within 4.6%. The proposed paradigm paves the way for meta-device design based on precise dispersion engineering, which has potential applications in spectrometers, broadband beam forming and steering, hyperspectral imaging, etc.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"34 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The evolution of dissipative soliton resonance from noise-like pulse via the saturable absorption to reverse saturable absorption transition within covalent organic framework saturable absorbers 在共价有机框架可饱和吸收体中，耗散孤子共振通过可饱和吸收到反向可饱和吸收的转变，从类似噪声的脉冲演化而来

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2024-11-16 DOI: 10.1016/j.cjph.2024.10.028

Hsuan-Sen Wang , Ahmed F.M. EL-Mahdy , Shiao-Wei Kuo , Wen-Hsuan Kuan , Kuei-Huei Lin , Gong-Ru Lin , Chao-Kuei Lee

In this study, for the first time, the dynamic evolution from noise-like pulses (NLPs) to dissipative soliton resonance (DSR) in an erbium-doped fiber laser system was observed and investigated by using a porphyrin/pyrene-linked covalent organic framework (COF) saturable absorber. Experimentally, by adjusting the pump power, the laser operation state was observed to be with a transition from NLPs to DSR. In addition, the correlation between the transition from NLPs to DSR and the variation from saturable absorption to reverse saturable absorption (RSA) within the COF material was analyzed, leading to the variation of absorption with increasing pump power playing a key role in this process. The competition mechanism between the spectral filtering effect and RSA was proposed, and the results observed agree quite well with the proposed model. This research not only reveals new features of pulse dynamics in fiber lasers but also highlights the potential of crystalline porous materials in nonlinear optical applications. It provides an important experimental foundation for further exploration of novel two-dimensional materials in the field of ultrafast optics.

本研究利用卟啉/芘连接的共价有机框架（COF）可饱和吸收体，首次观察和研究了掺铒光纤激光器系统从类噪声脉冲（NLP）到耗散孤子共振（DSR）的动态演化过程。实验结果表明，通过调节泵浦功率，激光器的工作状态可以从 NLPs 过渡到 DSR。此外，还分析了从 NLPs 到 DSR 的转变与 COF 材料内部从可饱和吸收到反向可饱和吸收（RSA）的变化之间的相关性，从而得出吸收随泵浦功率增加而变化在这一过程中起着关键作用。提出了光谱滤波效应与 RSA 之间的竞争机制，观察到的结果与提出的模型相当吻合。这项研究不仅揭示了光纤激光器中脉冲动力学的新特征，还凸显了晶体多孔材料在非线性光学应用中的潜力。它为进一步探索新型二维材料在超快光学领域的应用提供了重要的实验基础。

{"title":"The evolution of dissipative soliton resonance from noise-like pulse via the saturable absorption to reverse saturable absorption transition within covalent organic framework saturable absorbers","authors":"Hsuan-Sen Wang , Ahmed F.M. EL-Mahdy , Shiao-Wei Kuo , Wen-Hsuan Kuan , Kuei-Huei Lin , Gong-Ru Lin , Chao-Kuei Lee","doi":"10.1016/j.cjph.2024.10.028","DOIUrl":"10.1016/j.cjph.2024.10.028","url":null,"abstract":"<div><div>In this study, for the first time, the dynamic evolution from noise-like pulses (NLPs) to dissipative soliton resonance (DSR) in an erbium-doped fiber laser system was observed and investigated by using a porphyrin/pyrene-linked covalent organic framework (COF) saturable absorber. Experimentally, by adjusting the pump power, the laser operation state was observed to be with a transition from NLPs to DSR. In addition, the correlation between the transition from NLPs to DSR and the variation from saturable absorption to reverse saturable absorption (RSA) within the COF material was analyzed, leading to the variation of absorption with increasing pump power playing a key role in this process. The competition mechanism between the spectral filtering effect and RSA was proposed, and the results observed agree quite well with the proposed model. This research not only reveals new features of pulse dynamics in fiber lasers but also highlights the potential of crystalline porous materials in nonlinear optical applications. It provides an important experimental foundation for further exploration of novel two-dimensional materials in the field of ultrafast optics.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"92 ","pages":"Pages 1267-1274"},"PeriodicalIF":4.6,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

GUP deformed background dynamics of phantom field 幻影场的 GUP 变形背景动态

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

General Relativity and Gravitation

Pub Date : 2024-11-16 DOI: 10.1007/s10714-024-03324-7

Gaurav Bhandari, S. D. Pathak, Manabendra Sharma, Anzhong Wang

Quantum gravity has been baffling the theoretical physicist for decades now, both for its mathematical obscurity and phenomenological testing. Nevertheless, the new era of precision cosmology presents a promising avenue to test the effects of quantum gravity. In this study, we consider a bottom-up approach. Without resorting to any candidate quantum gravity, we invoke a generalized uncertainty principle (GUP) directly into the cosmological Hamiltonian for a universe sourced by a phantom scalar field with potential to study the evolution of the universe in a very early epoch. This is followed by a systematic analysis of the dynamics, both qualitatively and quantitatively. Our qualitative analysis shows that the introduction of GUP significantly alters the existence of fixed points for the potential considered in this paper. In addition, we confirm the existence of an inflationary phase and analyze the behavior of relevant cosmological parameters with respect to the strength of the GUP distortion.

几十年来，量子引力一直困惑着理论物理学家，无论是其数学上的晦涩还是现象学上的检验。然而，新时代的精密宇宙学为检验量子引力的效应提供了一条大有可为的途径。在这项研究中，我们考虑了一种自下而上的方法。在不诉诸任何候选量子引力的情况下，我们将广义不确定性原理（GUP）直接引用到一个宇宙学哈密顿中，这个宇宙学哈密顿由一个幽灵标量场提供，具有研究宇宙在非常早期的演化的潜力。随后，我们从定性和定量两个方面对动力学进行了系统分析。我们的定性分析显示，GUP 的引入极大地改变了本文所考虑的势的定点存在。此外，我们还证实了暴胀阶段的存在，并分析了相关宇宙学参数与 GUP 扭曲强度有关的行为。

引用次数: 0

Large Optical Nonlinearity Enhancement and All-Optical Logic Gate Implementation in Silver-Modified Violet Phosphorus 银改性紫磷中的大光学非线性增强和全光逻辑门实现

IF 11 1区物理与天体物理 Q1 OPTICS

Laser & Photonics Reviews

Pub Date : 2024-11-16 DOI: 10.1002/lpor.202401521

Xiaodan Xu, Zexin Cui, Yifan Yang, Yaqing Zhang, Qifan Li, Lihua Tong, Jun Li, Xinzheng Zhang, Yanling Wu

As the most stable allotrope of phosphorus, violet phosphorus (VP) has attracted extensive research in the field of all-optical modulation due to its excellent broadband spatial self-phase modulation (SSPM) effect. To better exploit the great potential of VP in nonlinear photonics devices, this work explores chemical doping method to artificially enhance the nonlinear optical response of VP. Herein, silver-modified few-layer VP (Ag-VP) is constructed for SSPM experiments. In comparison to pristine VP, a significantly improved third-order nonlinear susceptibility (χ⁽³⁾) and nonlinear optical response for Ag-VP is obtained in visible light band, and the enhancement ratio increases with the increase of wavelength. Moreover, the excitation threshold of SSPM effect is also significantly reduced, with a reduction ratio up to 3.61. The enhanced nonlinear optical response is attributed to the improved light–matter interaction induced by impurity energy levels. By taking advantage of the outstanding SSPM effect of Ag-VP, an all-optical logic gate is designed to demonstrate “OR” logical information transmission. This work provides a new avenue for the design and application of energy-saving and tunable nonlinear photonic devices in the future.

紫磷（VP）是最稳定的磷同素异形体，因其出色的宽带空间自相位调制（SSPM）效应，在全光调制领域吸引了广泛的研究。为了更好地利用 VP 在非线性光子器件中的巨大潜力，本研究探索了化学掺杂法来人工增强 VP 的非线性光学响应。本文构建了银修饰的几层 VP（Ag-VP），用于 SSPM 实验。与原始 VP 相比，Ag-VP 在可见光波段的三阶非线性感度（χ(3)）和非线性光学响应得到了明显改善，且增强率随波长的增加而增加。此外，SSPM 效应的激发阈值也显著降低，降低比高达 3.61。非线性光学响应的增强归因于杂质能级诱导的光物质相互作用的改善。利用 Ag-VP 的出色 SSPM 效应，设计出了一种全光逻辑门，用于演示 "OR "逻辑信息传输。这项研究为未来设计和应用节能、可调谐的非线性光子器件提供了一条新途径。

{"title":"Large Optical Nonlinearity Enhancement and All-Optical Logic Gate Implementation in Silver-Modified Violet Phosphorus","authors":"Xiaodan Xu, Zexin Cui, Yifan Yang, Yaqing Zhang, Qifan Li, Lihua Tong, Jun Li, Xinzheng Zhang, Yanling Wu","doi":"10.1002/lpor.202401521","DOIUrl":"https://doi.org/10.1002/lpor.202401521","url":null,"abstract":"As the most stable allotrope of phosphorus, violet phosphorus (VP) has attracted extensive research in the field of all-optical modulation due to its excellent broadband spatial self-phase modulation (SSPM) effect. To better exploit the great potential of VP in nonlinear photonics devices, this work explores chemical doping method to artificially enhance the nonlinear optical response of VP. Herein, silver-modified few-layer VP (Ag-VP) is constructed for SSPM experiments. In comparison to pristine VP, a significantly improved third-order nonlinear susceptibility (χ(3)) and nonlinear optical response for Ag-VP is obtained in visible light band, and the enhancement ratio increases with the increase of wavelength. Moreover, the excitation threshold of SSPM effect is also significantly reduced, with a reduction ratio up to 3.61. The enhanced nonlinear optical response is attributed to the improved light–matter interaction induced by impurity energy levels. By taking advantage of the outstanding SSPM effect of Ag-VP, an all-optical logic gate is designed to demonstrate “OR” logical information transmission. This work provides a new avenue for the design and application of energy-saving and tunable nonlinear photonic devices in the future.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"112 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dark Current Suppression in Two-dimensional Histamine Lead Iodine Perovskite Single Crystal for X-ray Detection and Imaging 用于 X 射线探测和成像的二维组胺铅碘包荧光单晶中的暗电流抑制技术

IF 11 1区物理与天体物理 Q1 OPTICS

Laser & Photonics Reviews

Pub Date : 2024-11-16 DOI: 10.1002/lpor.202401365

Jun'an Lai, Sijun Cao, Shiji Zhou, Peng He, Kang An, Peng Feng, Daofu Wu, Yongqiang Zhou, Mengyue Wu, Qiang Huang, Xiaosheng Tang

Lead halide perovskites have emerged as attractive X-ray detector materials, owing to properties such as strong X-ray stopping power, excellent carrier transport, and high sensitivity. Additionally, they can be easily prepared by using solution-based synthesis approaches. However, traditional 3D (three-dimensional) perovskites X-ray detectors have shown limited application due to high dark currents generated under bias voltage as a result of strong ion migration. In this work, an X-ray detector with a vertical structure device is demonstrated using 2D (two-dimensional) histamine lead halide perovskite single crystal HAPbI₄ (HPI, HA = histamine). Due to the dielectric screening effect of diamine and the vertical structure of the HPI device, the fabricated detector shows a sensitivity of 7737 µC Gy_air⁻¹ cm⁻² under a bias voltage of 30 V. Furthermore, the detector shows a sensitivity of 293 µC Gy_air⁻¹ cm⁻² and detection limit of 51.38 nGy_air s⁻¹ without bias voltage, wherein the dark current is almost completely suppressed. All of these properties indicate the X-ray detection device is a promising candidate for next-generation optoelectronic applications.

卤化铅包晶石具有强大的 X 射线阻挡能力、出色的载流子传输和高灵敏度等特性，已成为极具吸引力的 X 射线探测器材料。此外，它们还可以通过溶液合成法轻松制备。然而，传统的三维（three-dimensional）包云石 X 射线探测器由于离子迁移强而在偏置电压下产生高暗电流，因此应用有限。在这项研究中，利用二维组胺卤化铅包晶石单晶 HAPbI4（HPI，HA = 组胺）展示了一种垂直结构器件的 X 射线探测器。由于二胺的介电屏蔽效应和 HPI 器件的垂直结构，在 30 V 的偏置电压下，所制造的探测器显示出 7737 µC Gyair-1 cm-2 的灵敏度。此外，该探测器在无偏压情况下的灵敏度为 293 µC Gyair-1 cm-2，探测极限为 51.38 nGyair s-1，暗电流几乎完全被抑制。所有这些特性表明，该 X 射线探测装置有望成为下一代光电应用的候选器件。

{"title":"Dark Current Suppression in Two-dimensional Histamine Lead Iodine Perovskite Single Crystal for X-ray Detection and Imaging","authors":"Jun'an Lai, Sijun Cao, Shiji Zhou, Peng He, Kang An, Peng Feng, Daofu Wu, Yongqiang Zhou, Mengyue Wu, Qiang Huang, Xiaosheng Tang","doi":"10.1002/lpor.202401365","DOIUrl":"https://doi.org/10.1002/lpor.202401365","url":null,"abstract":"Lead halide perovskites have emerged as attractive X-ray detector materials, owing to properties such as strong X-ray stopping power, excellent carrier transport, and high sensitivity. Additionally, they can be easily prepared by using solution-based synthesis approaches. However, traditional 3D (three-dimensional) perovskites X-ray detectors have shown limited application due to high dark currents generated under bias voltage as a result of strong ion migration. In this work, an X-ray detector with a vertical structure device is demonstrated using 2D (two-dimensional) histamine lead halide perovskite single crystal HAPbI4 (HPI, HA = histamine). Due to the dielectric screening effect of diamine and the vertical structure of the HPI device, the fabricated detector shows a sensitivity of 7737 µC Gyair−1 cm−2 under a bias voltage of 30 V. Furthermore, the detector shows a sensitivity of 293 µC Gyair−1 cm−2 and detection limit of 51.38 nGyair s−1 without bias voltage, wherein the dark current is almost completely suppressed. All of these properties indicate the X-ray detection device is a promising candidate for next-generation optoelectronic applications.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"8 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tailoring structural, morphological, and magnetic properties of Sr0.54Ca0.46Fe6.5-xNixAl5.5O19 hexaferrites via Ni substitution 通过镍替代调整 Sr0.54Ca0.46Fe6.5-xNixAl5.5O19 六元晶的结构、形态和磁性能

IF 2.1 4区物理与天体物理 Q3 PHYSICS, CONDENSED MATTER

Solid State Communications

Pub Date : 2024-11-16 DOI: 10.1016/j.ssc.2024.115760

S. Elkhouad , Z. Yamkane , M. Sadik , R. Moubah , M. Moutataouia , H. Lassri , L. Bessais , J. Horcheni , H. Jaballah , M. Abdellaoui

Sr_0.54Ca_0,46Fe_6.5-xNi_xAl_5.5O₁₉ (0 ≤ x ≤ 0.3) hexaferrite powders were prepared by the sol-gel auto combustion method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Magnetic measurements were performed with physical properties measurement system (PPMS). The lattice parameters, volume, and lattice strain were calculated. XRD analyses revealed a reduction in crystallite size with increasing Ni content. Interestingly, the magnetic analysis indicated that nickel, with its low magnetic moment, significantly enhanced the magnetization of Sr_0.54Ca_0.46Fe_6.5-xNi_xAl_5.5O₁₉ (0.0 ≤ x ≤ 0.3) and reduced the coercive field. Furthermore, the Law of Approach to Saturation (LAS) theory was employed to extract the first anisotropy constant, the anisotropy field, and several essential magnetic parameters, providing valuable insights into the magnetic behavior of samples.

采用溶胶-凝胶自动燃烧法制备了 Sr0.54Ca0,46Fe6.5-xNixAl5.5O19 (0 ≤ x ≤ 0.3) 六价铁氧体粉末，并使用 X 射线衍射 (XRD)、扫描电子显微镜 (SEM) 和能量色散 X 射线光谱 (EDX) 对其进行了表征。磁性测量采用物理性质测量系统（PPMS）进行。计算了晶格参数、体积和晶格应变。XRD 分析表明，随着镍含量的增加，晶粒尺寸减小。有趣的是，磁性分析表明，镍的低磁矩显著增强了 Sr0.54Ca0.46Fe6.5-xNixAl5.5O19（0.0 ≤ x ≤ 0.3）的磁化，并降低了矫顽力场。此外，还利用饱和定律（LAS）理论提取了第一各向异性常数、各向异性场和几个基本磁性参数，为了解样品的磁性行为提供了宝贵的见解。

{"title":"Tailoring structural, morphological, and magnetic properties of Sr0.54Ca0.46Fe6.5-xNixAl5.5O19 hexaferrites via Ni substitution","authors":"S. Elkhouad , Z. Yamkane , M. Sadik , R. Moubah , M. Moutataouia , H. Lassri , L. Bessais , J. Horcheni , H. Jaballah , M. Abdellaoui","doi":"10.1016/j.ssc.2024.115760","DOIUrl":"10.1016/j.ssc.2024.115760","url":null,"abstract":"<div><div>Sr0.54Ca0,46Fe6.5-xNixAl5.5O19 (0 ≤ x ≤ 0.3) hexaferrite powders were prepared by the sol-gel auto combustion method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Magnetic measurements were performed with physical properties measurement system (PPMS). The lattice parameters, volume, and lattice strain were calculated. XRD analyses revealed a reduction in crystallite size with increasing Ni content. Interestingly, the magnetic analysis indicated that nickel, with its low magnetic moment, significantly enhanced the magnetization of Sr0.54Ca0.46Fe6.5-xNixAl5.5O19 (0.0 ≤ x ≤ 0.3) and reduced the coercive field. Furthermore, the Law of Approach to Saturation (LAS) theory was employed to extract the first anisotropy constant, the anisotropy field, and several essential magnetic parameters, providing valuable insights into the magnetic behavior of samples.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"396 ","pages":"Article 115760"},"PeriodicalIF":2.1,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Time persistence of climate and carbon flux networks 气候和碳通量网络的时间持久性

IF 5.4 1区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Communications Physics

Pub Date : 2024-11-16 DOI: 10.1038/s42005-024-01862-9

Ting Qing, Fan Wang, Qiuyue Li, Gaogao Dong, Lixin Tian, Shlomo Havlin

The persistence of the global climate system is critical for assuring the sustainability of the natural ecosystem. However, persistence at a network level has been rarely discussed. Here we develop a framework to analyze the time persistence of the yearly networks of climate and carbon flux, based on cross-correlations between sites, using daily data from China, the contiguous United States, and the Europe land region. Our framework for determining the persistence is based on analyzing the similarity between the network structures in different years. Our results reveal that the similarity of climate and carbon flux networks in different years are within the range of 0.57 ± 0.07, implying that the climate and carbon flux in the Earth’s climate system are generally persistent and in a steady state. We find a very small decay in similarity when the gap between years increases. Moreover, we find that the persistence of climate variables and carbon flux in the three regions decreases when considering only long range links. Analyzing the persistence and evolution of the climate and carbon flux networks, enhance our understanding of the spatial and temporal evolution of the global climate system. The persistence of the global climate system is essential for the sustainability of natural ecosystems. This work develops a framework, generate climate and carbon flux networks and finds that the similarity of the networks in different years is 0.57 ± 0.07, implying that the system is generally stable and that the similarity decay is very small when the year gap increases.

全球气候系统的持久性对于确保自然生态系统的可持续性至关重要。然而，在网络层面上的持续性却很少被讨论。在此，我们利用中国、美国毗连地区和欧洲陆地地区的每日数据，基于站点之间的交叉相关性，建立了一个分析气候和碳通量年度网络时间持续性的框架。我们确定持续性的框架是基于对不同年份网络结构相似性的分析。我们的结果表明，不同年份的气候和碳通量网络相似度在 0.57 ± 0.07 的范围内，这意味着地球气候系统中的气候和碳通量总体上是持久的，处于稳定状态。我们发现，当年份之间的差距增大时，相似性的衰减非常小。此外，我们还发现，如果只考虑长程联系，三个地区气候变量和碳通量的持续性会降低。分析气候和碳通量网络的持续性和演化，有助于加深我们对全球气候系统时空演化的理解。全球气候系统的持久性对自然生态系统的可持续性至关重要。本研究建立了一个框架，生成了气候和碳通量网络，并发现不同年份网络的相似度为 0.57 ± 0.07，这意味着系统总体上是稳定的，而且当年份差距增大时，相似度衰减非常小。

{"title":"Time persistence of climate and carbon flux networks","authors":"Ting Qing, Fan Wang, Qiuyue Li, Gaogao Dong, Lixin Tian, Shlomo Havlin","doi":"10.1038/s42005-024-01862-9","DOIUrl":"10.1038/s42005-024-01862-9","url":null,"abstract":"The persistence of the global climate system is critical for assuring the sustainability of the natural ecosystem. However, persistence at a network level has been rarely discussed. Here we develop a framework to analyze the time persistence of the yearly networks of climate and carbon flux, based on cross-correlations between sites, using daily data from China, the contiguous United States, and the Europe land region. Our framework for determining the persistence is based on analyzing the similarity between the network structures in different years. Our results reveal that the similarity of climate and carbon flux networks in different years are within the range of 0.57 ± 0.07, implying that the climate and carbon flux in the Earth’s climate system are generally persistent and in a steady state. We find a very small decay in similarity when the gap between years increases. Moreover, we find that the persistence of climate variables and carbon flux in the three regions decreases when considering only long range links. Analyzing the persistence and evolution of the climate and carbon flux networks, enhance our understanding of the spatial and temporal evolution of the global climate system. The persistence of the global climate system is essential for the sustainability of natural ecosystems. This work develops a framework, generate climate and carbon flux networks and finds that the similarity of the networks in different years is 0.57 ± 0.07, implying that the system is generally stable and that the similarity decay is very small when the year gap increases.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-10"},"PeriodicalIF":5.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01862-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regulating Second-Harmonic Generation in 2D Chiral Perovskites Through Achiral Organic Spacer Cation Alloying Strategy 通过手性有机间隔阳离子合金化策略调控二维手性包光体中的二次谐波发生

IF 11 1区物理与天体物理 Q1 OPTICS

Laser & Photonics Reviews

Pub Date : 2024-11-16 DOI: 10.1002/lpor.202401379

Junzi Li, Zhihang Guo, Meiting Wang, Yonghong Shao, Yi Chen, Yan Qin, Wenjing Zhang, Changshun Wang, Hao Jin, Luyang Wang, Tingchao He

The inherent structural flexibility and chiroptical activity of 2D chiral perovskites make them promising for the nonlinear optical (NLO) application. A comprehensive understanding of the second-harmonic generation (SHG) mechanism in 2D chiral perovskites is essential for developing NLO devices. However, the rational design of 2D chiral perovskite structures to regulate SHG properties remains challenging. Herein, to regulate SHG response, an achiral organic spacer cation alloying strategy is employed to construct a series of 2D chiral perovskites. Through the measurement of temperature-dependent photoluminescence (PL) spectra, it is revealed that the material design strategy can effectively modulating self-trapped exciton (STE) emission. More importantly, it is confirmed that there is a competitive relationship between STE emission and SHG in 2D chiral perovskites. Meanwhile, the microscopic imaging of circularly polarized-SHG is demonstrated in chiral perovskites. This work will not only advance the understanding of the SHG mechanism in 2D chiral perovskites but also provide inspiration for the rational design and synthesis of perovskites for NLO devices.

二维手性包光体固有的结构灵活性和自旋光学活性使其在非线性光学（NLO）应用中大有可为。全面了解二维手性包光体中的二次谐波发生（SHG）机制对于开发 NLO 器件至关重要。然而，如何合理设计二维手性包晶结构以调节 SHG 特性仍然是一项挑战。在本文中，为了调节 SHG 响应，我们采用了非手性有机间隔阳离子合金化策略来构建一系列二维手性包光体。通过测量随温度变化的光致发光（PL）光谱，发现该材料设计策略能有效调节自俘获激子（STE）发射。更重要的是，研究证实了二维手性包光体中的 STE 发射与 SHG 之间存在竞争关系。同时，在手性包晶石中演示了圆偏振-SHG 的显微成像。这项工作不仅将推进人们对二维手性包晶中 SHG 机制的理解，还将为合理设计和合成用于 NLO 器件的包晶提供灵感。

{"title":"Regulating Second-Harmonic Generation in 2D Chiral Perovskites Through Achiral Organic Spacer Cation Alloying Strategy","authors":"Junzi Li, Zhihang Guo, Meiting Wang, Yonghong Shao, Yi Chen, Yan Qin, Wenjing Zhang, Changshun Wang, Hao Jin, Luyang Wang, Tingchao He","doi":"10.1002/lpor.202401379","DOIUrl":"https://doi.org/10.1002/lpor.202401379","url":null,"abstract":"The inherent structural flexibility and chiroptical activity of 2D chiral perovskites make them promising for the nonlinear optical (NLO) application. A comprehensive understanding of the second-harmonic generation (SHG) mechanism in 2D chiral perovskites is essential for developing NLO devices. However, the rational design of 2D chiral perovskite structures to regulate SHG properties remains challenging. Herein, to regulate SHG response, an achiral organic spacer cation alloying strategy is employed to construct a series of 2D chiral perovskites. Through the measurement of temperature-dependent photoluminescence (PL) spectra, it is revealed that the material design strategy can effectively modulating self-trapped exciton (STE) emission. More importantly, it is confirmed that there is a competitive relationship between STE emission and SHG in 2D chiral perovskites. Meanwhile, the microscopic imaging of circularly polarized-SHG is demonstrated in chiral perovskites. This work will not only advance the understanding of the SHG mechanism in 2D chiral perovskites but also provide inspiration for the rational design and synthesis of perovskites for NLO devices.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"51 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pyroelectrically Driven Charge Transfer and its Advantages on SERS and Self-Cleaning Property 热释电驱动电荷转移及其对 SERS 和自清洁性能的优势

IF 11 1区物理与天体物理 Q1 OPTICS

Laser & Photonics Reviews

Pub Date : 2024-11-16 DOI: 10.1002/lpor.202401152

Yang Wu, Tianyu Sun, Mingrui Shao, Chang Ji, Chonghui Li, Chao Zhang, Zhen Li

The fabrication of reusable SERS substrates with sensitivity at the single-molecule level remains challenging but promising. Herein, a composite surface-enhanced Raman scattering (SERS) substrate is proposed that includes Ag nanoparticle (Ag NPs) /Graphene/BaTiO₃ (Ag/G/BTO) from a chemical enhancement perspective. The pyroelectric field generated by BaTiO₃ drives the charge transfer between the SERS substrate and molecules, achieving a significant improvement in the SERS performance and self-cleaning properties. The SERS signals of rhodamine 6G (R6G) molecules are further amplified up to 70-fold. Thus, the detection limit is reduced by three orders of magnitude in this study, reaching 10⁻¹⁴ m after applying a pyroelectric field. In addition, the substrate exhibits a higher degradation efficiency than previous self-cleaning SERS substrates because of the outstanding catalytic properties of BaTiO₃. Target molecules are degraded effectively after several temperature cycles. A detailed mechanism analysis of pyroelectric SERS is conducted based on theoretical simulations and experimental results. This study is considered to deepen the understanding of SERS mechanisms and boost the application of SERS technology.

制造具有单分子级灵敏度的可重复使用的 SERS 基底仍具有挑战性，但前景广阔。本文从化学增强的角度出发，提出了一种包括银纳米粒子（Ag NPs）/石墨烯/BaTiO3（Ag/G/BTO）的复合表面增强拉曼散射（SERS）基底。BaTiO3 产生的热电场推动了 SERS 基底与分子之间的电荷转移，从而显著提高了 SERS 性能和自清洁特性。罗丹明 6G (R6G) 分子的 SERS 信号被进一步放大了 70 倍。因此，本研究中的检测限降低了三个数量级，在施加热释电场后达到 10-14 m。此外，由于 BaTiO3 具有出色的催化特性，与之前的自清洁 SERS 基底相比，该基底具有更高的降解效率。目标分子在经过多次温度循环后可被有效降解。基于理论模拟和实验结果，对热释电 SERS 进行了详细的机理分析。该研究有助于加深对 SERS 机理的理解，促进 SERS 技术的应用。

{"title":"Pyroelectrically Driven Charge Transfer and its Advantages on SERS and Self-Cleaning Property","authors":"Yang Wu, Tianyu Sun, Mingrui Shao, Chang Ji, Chonghui Li, Chao Zhang, Zhen Li","doi":"10.1002/lpor.202401152","DOIUrl":"https://doi.org/10.1002/lpor.202401152","url":null,"abstract":"The fabrication of reusable SERS substrates with sensitivity at the single-molecule level remains challenging but promising. Herein, a composite surface-enhanced Raman scattering (SERS) substrate is proposed that includes Ag nanoparticle (Ag NPs) /Graphene/BaTiO3 (Ag/G/BTO) from a chemical enhancement perspective. The pyroelectric field generated by BaTiO3 drives the charge transfer between the SERS substrate and molecules, achieving a significant improvement in the SERS performance and self-cleaning properties. The SERS signals of rhodamine 6G (R6G) molecules are further amplified up to 70-fold. Thus, the detection limit is reduced by three orders of magnitude in this study, reaching 10−14 m after applying a pyroelectric field. In addition, the substrate exhibits a higher degradation efficiency than previous self-cleaning SERS substrates because of the outstanding catalytic properties of BaTiO3. Target molecules are degraded effectively after several temperature cycles. A detailed mechanism analysis of pyroelectric SERS is conducted based on theoretical simulations and experimental results. This study is considered to deepen the understanding of SERS mechanisms and boost the application of SERS technology.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"7 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

All-optical image transmission through a dynamically perturbed multimode fiber and a ring-core fiber using diffractive deep neural networks. 利用衍射深度神经网络，通过动态扰动多模光纤和环芯光纤进行全光图像传输。

IF 3.1 2区物理与天体物理 Q2 OPTICS

Optics letters

Pub Date : 2024-11-15 DOI: 10.1364/OL.541194

Jianping Zhu, Lei Zhu, Ran Gao, Xishuo Wang, Jianxin Ren, Shuaidong Chen, Zexuan Jing, Zhipei Li, Shanting Hu, Qinghua Tian, Bo Tian, Huan Chang, Dong Guo, Xiaolong Pan, Zheyu Wu, Xiangjun Xin, Bo Liu

In this study, we present an all-optical image reconstruction technique leveraging a diffractive deep neural network (D2NN) within a ring-core fiber (RCF) architecture. Orbital angular momentum (OAM) modes are employed to facilitate imaging transmission. We experimentally validate the efficacy of our approach for complex field diffractive image reconstruction through a multimode fiber (MMF) and RCF at a 1550 nm operating wavelength. The experimental results demonstrate the superior performance of the proposed method in mitigating RCF scattering-to-restoration transformation issues, significantly outperforming traditional MMF-based imaging correction techniques.

在这项研究中，我们利用环芯光纤（RCF）架构中的衍射深度神经网络（D2NN），提出了一种全光学图像重建技术。采用轨道角动量（OAM）模式促进成像传输。我们通过实验验证了我们的方法在 1550 nm 工作波长下通过多模光纤（MMF）和 RCF 进行复杂场衍射图像重建的功效。实验结果表明，所提出的方法在缓解 RCF 散射到复原转换问题方面性能优越，明显优于传统的基于 MMF 的成像校正技术。

引用次数: 0

首页上一页

下一页尾页

类型

物理与天体物理最新文献

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

全部 ACS Photonics J. Biophotonics Laser Photonics Rev. Comput. Phys. Commun. J. Comput. Phys. Prog. Part. Nucl. Phys. Prog. Quantum Electron. Solid State Commun. IEEE Trans. Plasma Sci. Acoust. Phys. Appl. Magn. Reson. Astrophys. Bull. ASTROPHYSICS+ Braz. J. Phys. B LEBEDEV PHYS INST+ Commun. Math. Phys. Dokl. Phys. EPJ QUANTUM TECHNOL Exp. Astron. Few-Body Syst. Found. Phys. FRONT PHYS-BEIJING Gen. Relativ. Gravitation Indian J. Phys. Int. J. Theor. Phys. Jetp Lett. J. Astrophys. Astron. J CONTEMP PHYS-ARME+ J. Exp. Theor. Phys. J. High Energy Phys. J. Low Temp. Phys. J. Russ. Laser Res. J. Stat. Phys. J. Supercond. Novel Magn. J KOREAN PHYS SOC Kinematics Phys. Celestial Bodies Lett. Math. Phys. Living Rev. Relativ. Living Rev. Sol. Phys. Moscow Univ. Phys. Bull. Opt. Rev. Opt. Spectrosc. Phys. At. Nucl. Phys. Part. Nucl. Phys. Solid State PHYS WAVE PHENOM Plasma Phys. Rep. Plasmonics Quantum Inf. Process. Russ. J. Math. Phys. Russ. Phys. J. SCI CHINA PHYS MECH Sol. Phys. Sol. Syst. Res. Tech. Phys. Tech. Phys. Lett. Theor. Math. Phys. ACTA PHYS SIN-CH ED Acta Phys. Pol. B 光学学报光子学报 Acta Phys. Pol. A Adv. Phys. ADV PHYS-X Adv. Condens. Matter Phys. Adv. High Energy Phys. Am. J. Phys. Ann. Phys. Annu. Rev. Condens. Matter Phys. Annu. Rev. Nucl. Part. Sci. Appl. Phys. Express Appl. Phys. Lett. Annu. Rev. Astron. Astrophys. ARCH ACOUST APL Photonics Appl. Phys. Rev. Ann. Phys. ASTRON ASTROPHYS Astrophys. J. Suppl. Ser. Astrophys. Space Sci. ASTROBIOLOGY Can. J. Phys. 液晶与显示 Chin. Phys. C Chin. Phys. B Classical Quantum Gravity CHIN OPT LETT Chin. J. Phys. Chin. Phys. Lett. Condens. Matter Phys. Commun. Phys. Commun. Theor. Phys. Contrib. Plasma Phys. Curr. Appl Phys. ENTROPY-SWITZ EPL-EUROPHYS LETT EUR PHYS J-SPEC TOP EUR PHYS J-APPL PHYS Front. Phys. High Pressure Res.

﹀