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张大伟课题组（超精密光学制造）2020年部分论文成果汇编
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2020年，本课题组在微纳结构设计及光场调控、微流控芯片制备及生物医学检测、新型成像方法及计算、以及光动力学诊疗、光催化、激光照明、光学检测/传感材料等光学领域发表二区以上SCI论文19篇，其中，一区论文4篇，二区论文15篇。
1. Polarization-independent highly efficient generation of Airy optical beams with dielectric metasurfaces
用偏振无关的介电质超构表面高效产生艾里光束
Binbin Yu, Jing Wen*, Lei Chen, Leihong Zhang, Yulong Fan, Bo Dai, Saima Kanwal, Dangyuan Lei, Dawei Zhang*,Photonics Research, 2020, 8, 7: 1148-1154
【SCI一区】【微纳结构设计及光场调控】
Abstract:Airy optical beams have emerged to draw enormous theoretical and experimental research interest due to itsoutstanding characteristics. Conventional approaches suffer from bulky and costly systems, as well as poor phasediscretization. The newly developed metasurface-based Airy beam generators have constraints of polarizationdependence or limited generation efficiency. Here, we experimentally demonstrate a polarization-independentsilicon dielectric metasurface for generation of high-efficiency Airy optical beams. In our implementation, ratherthan synchronous manipulation of the amplitude and phase by plasmonic or Huygens’ metasurfaces, we employand impose a 3/2 phase-only manipulation on the dielectric metasurface, consisting of an array of silicon nanopillars with an optimized transmission efficiency as high as 97%. The resultant Airy optical beams possess extraordinarily large deflection angles and relatively narrow beam widths. Our validated scheme will open up afascinating doorway to broaden the application scenarios of Airy optical beams on ultra-compact photonicplatforms.
摘要：本篇论文主要采用了将3/2纯相位调控方法代替同步控制振幅和相位的方法，将调控后的相位分布加载到传输型超表面结构单元中。经过实验验证，经设计的超表面后出射的艾里光束光场分布不随入射光偏振态变化而变化。并对实验所得光场分布进行三维重建，所形成的光束在一定传输范围内具有无衍射特性，传播路径近似于艾里函数包络线；传播路径经障碍物破坏后迅速复原。本文通过理论和实验验证了由偏振无关介电质超表面所生成的艾里光束较传统方法具有主瓣半高全宽小、高弯曲系数等优点，并且在高效生成艾里光束的同时，实现了器件小型化的目的，满足了基于艾里光束在激光加工、成像、粒子搬运等领域的集成化应用。
2. High throughput DNA concentration determination system based on fluorescence technology
基于荧光检测技术的高能量核酸浓度检测系统
Zhenqing Li, Pengbo Zhang, Bo Yang, Jiahui Liu, Heqi Xi, Dawei Zhang*, Yoshinori Yamaguchi,Sensors & Actuators: B. Chemical, 2021, 328: 128904
【SCI一区】【微流控芯片制备及生物医学检测】
Abstract: The measurement of DNA concentration is an important step in many research procedures in molecular biology. Traditional method for DNA concentration determination is based on ultraviolet absorbance which suffers from low sensitivity. Thus, we proposed a high throughput and low-cost DNA concentration system based on fluorescence technology. We analyzed the self-luminescence of each individual solution in DNA test kit, such as fluorescence dyes and DNA. It showed that the fluorescence emission from the dsDNA/dye complex was significantly higher than the self-luminescence from the single SYBR Green I, Gel Green and DNA solution when it was excited by laser diode source. SYBR Green I and Gel Green preferred CG bp sequences in dsDNA. dsDNA ranged from 2 to 15 ng/μL presented a stronger linear relationship with relative fluorescence intensity (R = 0.995). Such a low-cost system could measure the concentration of 24 DNA samples within 100 s. It permits the estimation of concentrations of DNA as low as 2 ng/μL and offers a simple way for DNA concentration determination during biological research, especially for the labs in the third world countries.
摘要：DNA浓度测量在分子生物学研究中重要的一个环节。传统的DNA深度测量是基于紫外吸光度法，该方法灵敏度低。为此，我们提出了一种基于荧光检测技术的高通量低成本的核酸浓度检测系统。在本论文中，我们分析了DNA浓度测量试剂(荧光染料、DNA)的自发光。结果表明，当采用激光二极管照射检测试剂时，荧光染料与DNA结合物的荧光远高于DNA和荧光染料(SYBR Green、Gel Green)的自发光。SYBR Green I和Gel Green荧光染料倾向于与鸟嘌呤（G）和胞嘧啶（C）结合。在浓度范围2-15 ng/μL内，双链DNA浓度与荧光光强显示了较好的线性关系(R=0.995)。该检测系统可以在100秒内完成24个样品浓度的快速测量，最低检测浓度可达2 ng/μL。本研究为生物学研究，特别是第三世界国家的生物实验室提供了一种简单的DNA浓度测量方法。
3.Ultrasound and Near-Infrared Light Dual-Triggered Upconversion Zeolite-Based Nanocomposite for Hyperthermia-Enhanced Multimodal Melanoma Therapy via a Precise Apoptotic Mechanism
超声和近红外光双触发上转换沸石基纳米复合材料用于多模式黑色素瘤治疗
Lulu Zheng, Yule Zhang, Hui Lin, Shifei Kang, Yuhao Li, Di Sun, Mengya Chen, Zixin Wang, Ziao Jiao, Yuwen Wang, Bo Dai, Songlin Zhuang, Dawei Zhang*, ACS Applied Materials & Interfaces, 2020, 12: 32420-32431
【SCI一区】【光动力学诊疗】
Abstract：High reactive oxygen species (ROS) generation efficiency and induction of targeted cell apoptosis are recognized as key objectives to achieve ahighly efficient strategy for cancer therapy with minimum side effects of inflammatory reactions. However, it is still a challenge to realize higher therapeutic efficiency with a cell apoptosis model. Herein, we present strong upconversion luminescent biosafe cores derived from Linde Type A (LTA) zeolites and modification with targeted/therapeutic drugs for multimodal therapy, in which sonodynamic therapy (SDT) combined with photodynamic therapy (PDT) increases therapeutic efficiency especially in deep sites of tumor via producing cytoplasmic ROS and mitochondrial superoxide and photothermal therapy (PTT) enhances PDT effects via higher fluorescence resonance energy transfer (FRET) efficacy attributed to an increased temperature. Furthermore, the transcriptomic analysis reveals that cellular internalization of the nanosystem can lead to tumor ablation via cell apoptosis. We expect that the multimodal therapy based on LTA zeolite drug nanocarriers could be applied in the cancer therapeutics in the nearfuture.
摘要：高效的产生活性氧族(ROS)依然是影响光动力治疗肿瘤效果的关键步骤。通过靶向诱导肿瘤细胞凋亡，跟传统的诱导肿瘤坏死的方法比较，能够显著抑制炎性风暴的产生，对机体的副作用较小。然而，建立高效产生ROS同时通过精准调控信号通路诱导细胞凋亡实现肿瘤抑制的光动力纳米材料系统是一个难点。本研究提出了通过Linda A型(LTA)沸石构建一种生物安全性好的上转换发光材料，通过靶向药物和治疗药物的修饰，实现光声联合的多模态可视化治疗模式。其中声动力疗法更适合在肿瘤深部产生治疗效果。另外，通过光热疗法实现肿瘤部位温度升高，进一步通过更高的荧光共振能量转移来增强光动力的作用。转录组学分析显示，细胞内化后的纳米材料可以通过诱导细胞凋亡信号通路上调，实现细胞凋亡导致肿瘤消融。该光动力治疗纳米材料体系结合荧光成像监控在肿瘤治疗领域有很大的应用潜力。
4.Diagnosis of mixed infections with swine viruses using an integrated microfluidic platform
基于集成式微流控平台的多种猪病诊断技术
Yongfeng Fu, Wei Li, Bo Dai, Lulu Zheng, Zhigang Zhang, Dongmei Qi, Xunjia Cheng, Dawei Zhang*, Songlin Zhuang, Sensors and Actuators B Chemical, 2020, 312, 128005
【SCI一区】【微流控芯片制备及生物医学检测】
Abstract：Early diagnosis and intervention of livestock epidemics is extremely important because disastrous outbreaks of an infectious disease can not only hit livestock industry but also cause a series of negative economic and social consequences. In order to fulfill the requirement of point-of-care testing, a reliable, field-portable, time-efficient and cost-effective microfluidic platform including a microfluidic chip and a semi-automated immunoassay system (SAIS) is developed. Multiple samples can be tested simultaneously in a single chip for multiple-biomarker testing. The entire assay, including reagent injection, well washing, waste collection and colorimetric detection, can be realized in the user-friendly system. The assay of three contagious diseases, PRRSV, CSFV and PCV2, is conducted in the microfluidic platform. The assay only takes 12 min and 4 μL of sample is required. The platform has the potential to be applied for on-site rapid screening livestock diseases.
摘要：牲畜流行病的早期诊断和干预极为重要，因为灾难性的传染病暴发不仅会打击畜牧业，还会造成一系列负面的经济和社会后果。本研究为了满足即时检验的要求，开发了一种可靠、现场便携式、省时且具有低成本的微流控检测平台，该平台包括微流体芯片和半自动免疫分析系统。该方案实现了在单个芯片中同时测试多个样品，并对每个样品进行多个生物标记物的同步检测。整个检测，包括试剂注入、清洗、废物收集和比色检测，都可以在该系统中实现。应用研究中，利用该微流控平台中进行了三种传染性疾病猪蓝耳病毒、猪瘟病毒和猪圆环病毒的检测。整个检测过程仅需12分钟，样品消耗只要4μL血样。该平台可被用于现场快速筛查牲畜疾病。
图1 多样品多指标酶联免疫检测生物芯片
图2 半自动免疫分析系统结构图
5.Rapid Quantitative Detection of Chloramphenicol in Milk by Microfluidic Immunoassay
基于微流控技术快速定量检测牛奶中的氯霉素
Mantong Zhao, Xiaolong Li, Yule Zhang, Yuwen Wang, Bo Wang, Lulu Zheng*, Dawei Zhang*, Songlin Zhuang, Food Chemistry,2021, 5,339: 127857
【SCI二区】【微流控芯片制备及生物医学检测】
Abstract: Chloramphenicol (CAP) is a toxic substance for human health, and detection of CAP residues in milk is necessary. However, most of the traditional CAP detection methods, such as high-performance liquid chromatography (HPLC), liquid/gas chromatography–tandem mass spectrometry (LC/GC–MS), enzyme-linked immunosorbent assay (ELISA) are time-consuming and complicated. Herein, an automated microfluidics system for CAP residue detection in milk was developed. The residual CAP of multiple milk samples was quantitatively detected via competitive immunoassay in a single microfluidic chip simultaneously with simple operation, and the reliability of the detection method was confirmed by flow cytometry. Completion of the detection by the system required less than 20 min and the cost of the microfluidic chip is US$12.3. The limit of detection was 0.05 µg L−1, and the recovery rate of CAP in milk ranged from 91.3%–105.5%. The microfluidic system developed in this study exhibited considerable potential in the point-of-care detection of CAP in milk.
摘要：氯霉素（CAP）严重危害人类的健康，因此检测牛奶中的CAP残留是非常有必要的。但是，传统的CAP检测方法，例如高效液相色谱（HPLC），液相/气相色谱-串联质谱（LC /GC–MS），酶联免疫吸附法（ELISA）等，所需检测时间很长而且操作非常复杂。在本研究中，提出了一种用于检测牛奶中CAP残留的自动化微流控检测系统。基于竞争免疫反应，通过简单的操作，就可以在微流控芯片中实现对多个牛奶样品中的CAP同时定量检测，并且采用流式细胞分析验证了该检测方法的可靠性。整个检测可以在20分钟内完成，并且微流控芯片的成本比较低，为12.3美元。检出限为0.05 µg L-1，牛奶中CAP的回收率为91.3％–105.5％。因此，在这项研究中所提出的微流控检测系统在牛奶中CAP的即时检测中展示了很大潜力。
牛奶中氯霉素微流控检测芯片
6.Polarization Insensitive, Broadband, Near Diffraction-Limited Metalens in Ultraviolet Region
紫外近衍射极限的偏振不敏感型超透镜
Saima Kanwal, JingWen, Binbin Yu, Xu Chen, Dileep Kumar, Yi Kang, Chunyan Bai, Saima Ubaid, Dawei Zhang*, Nanomaterials, 2020, 10, 8: 1439.
【SCI二区】【微纳结构设计及光场调控】
Abstract: Metasurfaces in the ultraviolet spectrum have stirred up prevalent research interest due to the increasing demand for ultra-compact and wearable UV optical systems. The limitations of conventional plasmonic metasurfaces operating in transmission mode can be overcome by using a suitable dielectric material. A metalens holds promising wavefront engineering for various applications. Metalenses have developed a breakthrough technology in the advancement of integrated and miniaturized optical devices. However, metalenses utilizing the Pancharatnam–Berry (PB) phase or resonance tuning methodology are restricted to polarization dependence and for various applications, polarization-insensitive metalenses are highly desirable. We propose the design of a high-efficiency dielectric polarization-insensitive UV metalens utilizing cylindrical nanopillars with strong focusing ability, providing full phase delay in a broadband range of Ultraviolet light (270–380 nm). The designed metalens comprises Silicon nitride cylindrical nanopillars with spatially varying radii and offers outstanding polarization-insensitive operation in the broadband UV spectrum. It will significantly promote and boost the integration and miniaturization of the UV photonic devices by overcoming the use of Plasmonics structures that are vulnerable to the absorption and ohmic losses of the metals. The focusing effiency of the designed metalens is as high as 40%.
摘要：随着对超紧凑可穿戴紫外光学系统的需求日益增长，紫外光谱超构表面引起了广泛的研究兴趣。使用合适的介质材料可以克服传统等离子体超构表面在传输模式下工作的局限性。超构透镜波前设计在各种应用中都很有前途。超构透镜在光学器件集成化和小型化方面取得了突破性进展。然而，利用Pancharatnam-Berry (PB)相位或共振调谐方法的超构透镜受到极化依赖的限制，对于各种应用，极化不敏感的超构透镜是非常必要的。本篇论文提出利用具有高效聚焦能力的圆柱形纳米柱设计一种高效率的极化不敏感介电紫外超构透镜，在宽带紫外光谱(270–380 nm)范围内提供全相位延迟。本文所设计的超构透镜具有半径变化的氮化硅圆柱形纳米管，并在宽带紫外光谱中提供出色的极化不敏感性能。它克服了等离子体结构易受金属吸收和欧姆损耗的影响，将极大地促进紫外光子器件的集成化和小型化。本文所设计超构透镜的聚焦效率高达40%。
7.High-Efficiency, Broadband, Near Diffraction-Limited, Dielectric Metalens in Ultraviolet Spectrum
紫外宽光谱近衍射极限的高效介电质超透镜
Saima Kanwal, JingWen*, Binbin Yu, Dileep Kumar, Xu Chen, Yi Kang, Chunyan Bai and Dawei Zhang*,Nanomaterials,2020, 10, 3: 490
【SCI二区】【微纳结构设计及光场调控】
Abstract:Ultraviolet (UV) optical devices have plenteous applications in the fields of nanofabrication, military, medical, sterilization, and others. Traditional optical components utilize gradual phase accumulation phenomena to alter the wave-front of the light, making them bulky, expensive, and inefficient. A dielectric metasurface could provide an auspicious approach to precisely control the amplitude, phase, and polarization of the incident light by abrupt, discrete phase changing with high efficiency due to low absorption losses. Metalenses, being one of the most attainable applications of metasurfaces, can extremely reduce the size and complexity of the optical systems. We present the design of a high-efficiency transmissive UV metalens operating in a broadband range of UV light (250–400 nm) with outstanding focusing characteristics. The polarization conversion efficiency of the nano-rod unit and the focusing efficiency of the metasurface are optimized to be as high as 96% and 77%, respectively. The off-axis focusing characteristics at different incident angles are also investigated. The designed metalens that is composed of silicon nitride nanorods will significantly uphold the advancement of UV photonic devices and can provide opportunities for the miniaturization and integration of the UV nanophotonics and its applications.
摘要：紫外(UV)光学器件在纳米制造、军事、医疗、灭菌等领域有着广泛的应用。传统光学元件利用连续渐变相位积累来改变光的波前，其体积大、价格昂贵、效率低下。介质超构表面由于吸收损耗低，可以通过突变、离散的相位变化，高效率地精确控制入射光的振幅、相位和偏振。作为最容易实现的超构表面应用之一，超构透镜可以极大地降低光学系统的尺寸和复杂性。本文设计了一种在250-400 nm宽紫外光范围内工作的高效紫外超构透镜，其具有出色的聚焦特性。优化后纳米棒单元的极化转换效率和超表面的聚焦效率分别达到96%和77%。且研究了不同入射角下的离轴聚焦特性。所设计的由氮化硅纳米棒组成的金属器件将极大地支持紫外光子器件的发展，并为紫外纳米光子器件的小型化、集成化及其应用提供机遇。
8.Dynamic tailoring of an optical skyrmion lattice in surface plasmon polaritons
表面等离激元中光学斯格明子晶格的动态剪裁
Chunyan Bai, Jian Chen, Yuxing Zhang, Saima Kanwal, Dawei Zhang*, Qiwen Zhan*,Optics Express,2020, 28, 7: 10320-10328
【SCI二区】【微纳结构设计及光场调控】
Abstract:Skyrmion is a topologically protected soliton with spin structures on the micro/nano scale that has promising applications in magnetic information storage and spintronics devices. This study focuses on the optical skyrmion lattice structures created in the surface plasmon polaritons (SPPs) field. Both the Néel-type optical skyrmion lattice formed by the electric field vector and Bloch-type optical skyrmion lattice formed by the magnetic field vector are generated via exciting a hexagonal grating structure on the metal surface with six Gaussian optical spots. Such a multiple-spot excitation can be realized through tightly focusing specially designed complex field with high NA lens. Through introducing phase shifting to the SPP excitation spots, the shape and position of the optical skyrmion lattice can be dynamically controlled. Both the electric field vector and magnetic field vector are evaluated quantitatively based on the electric fieldand magnetic fieldobtained by finite difference time domain (FDTD) simulation to demonstrate the validity and capability of the proposed technique.
摘要：斯格明子（Skyrmion）是一种具有微纳尺度自旋结构的受拓扑保护的孤子，在磁信息存储和自旋电子设备中具有广阔的应用前景。这项研究的重点是在表面等离子激元（SPPs）场中产生光学斯格明子晶格结构。电场矢量形成的Néel型斯格明子和磁场矢量形成的Bloch型斯格明子都可以通过激发金属表面上的旋转对称六边形光栅结构产生。这样的多点激发可以通过使用高NA物镜紧聚焦特殊设计的入射场来实现。此外通过将相移理论引入激发模型，可以动态地控制生成的光学斯格明子的形状和位置。文章基于有限差分时域（FDTD）仿真获得的电场和磁场，对电场矢量和磁场矢量进行定量评估，证明了该技术的有效性。
Fig. 3. The intensity distribution and the shape of the skyrmions are tailored in the electric field through adjusting the phase difference of the excitation beams. (a) (c) (e) The electric field intensity distributions mapped with in-plane electric field vector at the center of the grating structure. (b) (d) (f) The electric field vector skyrmion corresponding to the areas confined by black dotted line in (a) (c) (e), respectively.
图3.通过调节激发光束的相位差改变电场中斯格明子的强度分布和形状。（a）（c）（e）光栅结构中心处的电场强度和面内电场矢量分布。（b）（d）（f）分别对应于（a）（c）（e）中黑色虚线框区域内的三维电场矢量分布。
9.Shift of the surface plasmon polariton interference pattern in symmetrical arc slit structures and its application to Rayleigh metallic particle trapping
对称弧型狭缝结构中表面等离激元干涉图案的移动及其在瑞利金属粒子俘获中的应用
Chunyan Bai, Jian Chen, Yuxing Zhang, Saima Kanwal, Dawei Zhang*, Qiwen Zhan*,Optics Express,2020,28, 14: 21210-21219
【SCI二区】【微纳结构设计及光场调控】
Abstract: In symmetric nano/micro metal slits structures, interference patternsare produced by counter-propagating surface plasmon polaritons (SPPs) in the center of structures, which can be employed to improve the resolution of microscopy and surface etching, and to realize particle trapping. This paper focus on the shift of the SPP interference patterns in the symmetric arc slits structures. The excitation models with one incident beam and two incident beams are established and analyzed respectively, and methods to shift the SPP interference patterns via adjusting the tilt angle and initial phase of the excitation beams are compared. The FDTD simulation results show that these methods can precisely shift the SPP interference patterns in the symmetrical arc slits. Compared to the linear slits, the SPP waves arising from arc slits are stronger focused, resulting in a stronger gradient force. The characters of stronger focus and dynamic shifting of the focal spot make the symmetric arc slits structure has unique advantages in thecapture and transfer of the Rayleigh metallic particle.
摘要：在对称的微纳金属狭缝结构中，在结构的中心处相向传播的表面等离激元(SPPs)会产生干涉，这种干涉模式可用于提高表面刻蚀和显微成像的分辨率、实现粒子捕获。本文主要研究对称弧型狭缝结构中SPPs干涉图样的移动。分别建立和分析了单光束入射和双光束入射的激励模型，比较了通过调节入射光的倾斜角和初始相位来移动SPP干涉图样的方法。通过时域有限差分(FDTD)仿真结果证明，这些方法可以精确地控制对称弧型狭缝内SPP干涉图样的移动。与线性狭缝相比，弧型狭缝产生的SPP具有更强的聚焦特性，从而可以产生更强的梯度力。对称弧型狭缝结构的这种强聚焦和焦斑动态移动的特点，使其在瑞利金属粒子的捕捉和传递方面具有独特的优势。
Fig. 4. Transverse section of the SPP interference pattern in four arc slits structure (a) and four linear slits structure (c). Transverse profile intensity of the focus in arc slits structure (b). The intensity comparison of focus generated by arc slits and linear slits with different effective length (d). White dotted frames in the center of the structures indicate the focal spots.
图4.（a）四个弧型狭缝结构和（c）四个线型狭缝结构中SPP干涉图样的横截面图；（b）弧型狭缝结构中焦点沿x轴的横向轮廓强度；（d）有效长度相同的弧型狭缝和线型狭缝产生的聚焦强度比较。（a）和（c）中的白色虚线框表示焦点位置。
Fig. 6. Four arc slits are excited by corresponding excitation beams (a). The SPP interference pattern is shifted through adjusting the initial phase of the excitation beams (b-h). Black dashed lines indicate x = 0 and y=0.
图6. （a）四个弧型狭缝被相应的激发光束激发；（b-h）通过改变激发光束的初始相位实现SPP干涉焦点的移动。黑色虚线表示x = 0和y = 0。
10.Dynamic tailoring of an optical skyrmion lattice in surface plasmon polaritons: reply
表面等离激元中光学斯格明子晶格的动态剪裁：回复
Bai Chunyan, Chen Jian, Zhang Dawei*, Zhan Qiwen*, Optics Express,2020, 28, 22: 33616-33618【SCI二区】【微纳结构设计及光场调控】
Abstract: This is a Reply to the Comment by Meiler, Frank, and Giessen directed to a recent paper Dynamic tailoring of an optical skyrmion lattice in surface plasmon polaritons[ Opt.Express 28,10320(2020)] regarding to the existence of Bloch-type skyrmions in the magnetic field of surface plasmon polaritons.
摘要：这是对Meiler，Frank和Giessen针对最近一篇论文“对表面等离振子极化子中的光学Skyrmion晶格进行动态剪裁” [Opt.Express 28,10320(2020)]的评论的回复，关于表面等离子激元的磁场中的Bloch型Skyrmion的存在问题。
Fig.2. The distribution of the magnetic field at the center of the structure.(a) Re(H),(b)Re(Hx),(c) Re(Hz),(d) top view of vector distribution for the magnetic field,(e) perspective view of(d).
图2. 结构中心处的磁场分布。（a）Re(H)，（b）Re(Hx)，（c）Re(Hz)，（d）和（e）磁场矢量分布的俯视图和透视图。
11.Dynamical generation of multiple focal spot pairs with controllable position and polarization 动态生成可以调控位置和偏振的多个焦斑对
Yuxing Zhang, Jian Chen, Chunyan Bai, Dawei Zhang*, Qiwen Zhan*,Optics Express,2020,28, 18: 26706-26716【SCI二区】【微纳结构设计及光场调控】
Abstract: We report a flexible method todynamically generate multiple sub-wavelength focal spot pairs with adjustable polarization, position and number at the focal plane of a high numerical aperture (NA) objective lens.The desired incident field on the pupil plane can be analytically derived by employing the time-reversed method combined with the dipole antenna radiation theory. The numerical simulations of the corresponding tightly focused field are conducted using the Richards-Wolf vectorial diffraction theory. The validity of the presented methodis demonstrated through experimental generation of several designed pupil fields with a versatile vectorial optical field generator and characterization of the produced focused fields with Stokes parameter measurements.
摘要：我们汇报了一种灵活的方法，可以在高数值孔径物镜(NA)的焦平面上动态生成多个可控偏振、位置和数量的亚波长焦点对。通过将时间反转方法与偶极天线辐射理论相结合，可以解析得到在物镜光瞳平面处所需入射场。基于Richards-Wolf矢量衍射理论数值模拟相应的紧聚焦场。通过使用矢量光场发生器实验生成了所设计的光瞳场，并利用斯托克斯参数测量表征聚焦场的偏振态，证明了所提出方法的有效性。
图1 生成(a) 四个焦点和(d) 八个焦点所需光瞳平面处理想入射场。(b) 四个焦点和(e) 八个焦点的相应强度和偏振分布。(c) 沿着x轴和y轴对四个焦点强度的线扫描轮廓。(f) 沿x轴、y轴和对角线方向对八个焦点强度的线扫描轮廓。
图2 生成(a) 四个焦点和(d) 八个焦点所需瞳孔平面处入射场的实验结果。(b) 四个焦点和(e) 八个焦点的相应强度和偏振分布。(c) 四个焦点沿x轴和y轴的强度分布。(f) 八个焦点沿x轴、y轴和对角线方向的强度分布。
12.Research on image transmission mechanism through a multimode fiber based on principal component analysis
基于主成分分析的单根多模光纤图像传输机理研究
Leihong Zhang, Runchu Xu, Kaiming Wang, Banglian Xu, Ruisi Chen, Rohail Sarwar, Dawei Zhang*,Optics and Lasers in Engineering, 2020, 134: 106197
【SCI二区】【新型成像方法及计算】
Abstract: The real-time transmission of images through a multimode fiber (MMF) is still a challenging research work. One method completes image transmission by measuring and controlling the full complex field of the MMF. Another method uses artificial neural networks to train and construct the inverse transformation matrix of the MMF. However, the class of testing samples usually belongs to the same class used for the training. We propose a method that constructs the inverse transformation matrix of the MMF based on principal component analysis (PCA), which can reconstruct the grayscale images of natural scene at high frame rate and high resolution. Moreover, we use principal component analysis and support vector machine (PCA+SVM) to classify speckle patterns, and then images can be reconstructed based on the inverse transformation matrix of corresponding category. The PCA+SVM+PCA (PSP) method shows high reconstruction accuracy with few training samples. The proposed method demonstrates general imaging capability over a MMF lengths of 1 m, training time used to construct the inverse transformation matrix is short and the hardware requirements are low, which provides a feasible method for the MMF endoscope imaging.
摘要：在工业检测、光通信和医学成像等领域，通过多模光纤实时传输高分辨率的图像是一项具有挑战性的研究工作。一种方法通过对多模光纤传输的完整光场的测量和控制实现图像传输，但这需要大量先验知识；另一种方法使用神经网络训练传输矩阵，然而用于测试的图像与训练样本集通常属于同一类别。我们提出了一种基于主成分分析（PCA）构造多模光纤逆传输矩阵的方法，能够以高帧频、高分辨率传输自然场景的灰度图像，从而证明通用成像的能力。此外，我们使用主成分分析和支持向量机的方法（PCA+SVM）对散斑图像进行分类识别，进而重建原始图像。实验结果表明，属于同一类别的测试图像，仅需较少的训练样本即可获得较高的重建精度。我们的方法在1m长的多模光纤上具备通用成像的能力，构造逆传输矩阵所用的训练时间短，对硬件要求低，为多模光纤内窥镜成像提供了一种可行的方法。
图1 不同方法的图像重建示例
如图1所示，我们以鸟类、青蛙、微生物、人类运动、飞鹰和昆虫图像作为示例展示了原始图像、散斑图像和两种方法重建的测试图像。在图1中，第1行表示输入的原始图像，第二行表示输出的散斑图像，第三行和第四行分别表示PCA方法和CP方法（Caramazza P, et al. Nature Communications, 2019.）的重建图像，在每一个重建图像的下方，使用PSNR、SSIM和PCC作为量化指标评价图像的重建质量。由图1可知，对于作为示例的重建图像，我们提出的PCA方法和CP方法都能够在整个灰度级范围内显示出良好的重建效果。从主观上看，PCA方法重建图像的分辨率优于CP方法，PCA方法重建图像的细节再现较好，图像背景和整体的灰度值更加接近原始图像，而CP方法重建的图像细节丢失严重，图像的整体灰度级较低，图像偏暗。同时，相较于CP方法，我们的方法对硬件要求较低，40000个样本构造逆传输矩阵的训练为2.58h，而使用Nvidia Titanxp GPU的CP方法训练45000个样本的时间为48h，PCA方法仅需要其1/18的时间。
图2 图像重建示例（PSP方法和CP方法）
图2展示了从飞鹰、青蛙和微生物三类测试样本集中优选的重建图像与CP方法重建图像的质量比较。在图2中，第二列表示输入的原始图像，第三列表示输出的散斑图像，第四列表示PSP方法重建的图像，第5列表示CP方法重建的图像。与CP方法相比，优选的重建图像展示了对图像细节、图像背景和图像主体更高质量的恢复。如图3所示，我们从飞鹰、青蛙、人类运动、微生物和鸟类五类测试样本集中优选了重建质量较好的图片作为示例，展示了原始图像、散斑图像和重建图像。在图3中，第二列表示输入的原始图像，第三列表示输出的散斑图像，第四列表示分类后重建的图像，第5-7列表示20000、30000和40000训练样本重建的图像。由图可知，优选的分类后重建质量较好的图片和30000训练样本重建图像的质量近似，而每类的样本数目仅为其的4.7%。且因为测试图像与训练样本集属于同一类别，因此图像的背景再现较好，背景噪声较少。
图3图像重建示例（PSP方法和PCA方法）
13.Camouflaged Optical Encryption Based on Compressive Ghost Imaging
基于关联成像的光学伪装加密方案
Yi Kang, Leihong Zhang, Hualong Ye, Mantong Zhao, Kanwal Saima, Dawei Zhang∗, Optics and Lasers in Engineering, 2020, 6, 134: 106154【SCI二区】【新型成像方法及计算】
Abstract: A camouflaged encryption method based on ghost imaging is proposed. During the encryption process, a light source illuminates a camouflaged image with specific modulated patterns, and a generated sequence of intensity is transmitted to the receiver as a ciphertext. The ciphertext is captured by authorized receivers and potential eavesdroppers. Only authorized receivers with keys can obtain the secret image, while eavesdroppers can obtain camouflaged images only even if they steal the ciphertext and keys. The secret image is hidden by the camouflaged image, which protects the security of the secret image by confusing the eavesdropper. The feasibility and safety of this method in practical applications were verified by a series of simulations and experiments.
摘要：本文提出了一种基于鬼成像的伪装加密方法。加密方利用秘密信息所对应的密文调制生成新的编码方式，然后利用该光照模式加密伪装图像，将获得的强度矢量作为密文传输给接收方。密文被授权的接收方和潜在的攻击者获取。只有拥有密钥的授权接收者才能获得秘密信息，而攻击者即使窃取到密文和密钥也只能获得伪装图像。秘密图像巧妙地被伪装图像隐藏，从而提高了秘密图像的安全性。通过一系列的仿真和实验验证了该方案的在实际应用中的可行性和安全性。
图1 基于鬼成像的伪装加密方案示意图
14.A weakly supervised framework for abnormal behavior detection and localization in crowded scenes
拥挤场景中基于弱监督的框架的异常行为检测和定位
Xing Hu, Jian Dai, Yingping Huang, Haima Yang, Liang Zhang, Wenming Chen, Genke Yang, Dawei Zhang∗, Neurocomputing, 2020, 383, 28: 270-281
【SCI二区】【新型成像方法及计算】
Abstract：In this paper, a weakly supervised framework is proposed for Abnormal Behavior Detection and Localization (ABDL) in the scenes. First, the objects in the scene such as pedestrians, vehicles, etc. are detected using the Faster Regional Conventional Neural Network (Faster R-CNN); then, the object behavior is described by a Histogram of LargeScale Optical Flow (HLSOF) descriptor; finally, the Multiple Instance Support Vector Machine (MISVM) is trained and then used to identify the testing behaviors as normal or abnormal. Summarily, the proposed approach has three main advantages: (1) Benefit from the Faster R-CNN, our approach can analyze the behavior at object-wise, which makes our approach has good generality and high computational efficiency; (2) The HLSOF descriptor can characterize the object behavior efficiently, and is insensitive to the variations of the size of objects; (3) As a weakly supervised learning framework, the MISVM only requires the labels at the bag level rather than instance level, which makes our approach has high accuracy as the supervised approaches but not requires completely labeled training samples, only the frame-level label is required. Experimental results analysis on different datasets validates the effectiveness of our approach.
摘要：本文提出了一种用于场景异常行为检测和定位的弱监督框架。首先，使用更快的区域卷积神经网络(Faster R-CNN)检测场景中的物体，如行人、车辆等;然后，用大尺度光流描述子直方图描述目标行为;最后，利用多实例支持向量机(MISVM)进行训练，识别测试行为的正常或异常。总的来说，该方法具有三个主要优点:(1)得益于Faster R-CNN，我们的方法可以从对象的角度分析行为，这使得我们的方法具有良好的通用性和较高的计算效率;(2) HSOF描述符能够有效地描述对象的行为，对对象大小的变化不敏感;(3) MISVM作为弱监督学习框架，只需要包级的标签而不需要实例级的标签，这使得我们的方法与监督学习方法一样具有较高的准确性，但不需要完全标注的训练样本，只需要帧级标签。在不同数据集上的实验结果验证了该方法的有效性。
图一、设计的方块流程图
图二、方法效果及对比图
15.Highly Sensitive Graphene/Polydimethylsiloxane Composite Films near the Threshold Concentration with Biaxial Stretching
双轴拉伸近阈值浓度高灵敏墨烯/聚二甲基硅烷复合薄膜
Anqi Liu, Zhengji Ni, Juan Chen and Yuanshen Huang*,Polymers, 2020, 12, 1:71【SCI二区】【光学传感材料】
Abstract: Uniformly dispersed graphene effectively improves the strain-sensing capability of the composite film under a low graphene load in nanocomposites prepared with polydimethylsiloxane (PDMS) and graphene (GNP) monolayer powder. The threshold concentration of graphene was determined by loading nanocomposites at different temperatures. For different concentrations, when using traditional uniaxial stretching, the rate of resistance change of films near the threshold concentration is five times higher than the rate of films with a high concentration. Compared with traditional uniaxial stretching, the biaxial stretching we introduced can effectively improve the sensitivity of the film by an order of magnitude. The change in the resistance of the film near the threshold concentration is due to the change of the tunnel length and the cross-section of the tunnel, whereas the high concentration of the film is due to the change of the conductive path inside the film. Biaxial stretching has different effects on films with different concentrations, but the final effect of increasing sensitivity is the same. This study provides guidance for improving the strain-sensing sensitivity of GNP/PDMS composite films and the application of biaxial tension in detecting human motions.
摘要：低浓度的石墨烯均匀分散在由聚二甲基硅氧烷（PDMS）和石墨烯（GNP）制成的复合薄膜中可以有效提高薄膜的应变传感能力。薄膜中石墨烯的阈值浓度可以通过变温实验来确定。在不同浓度条件下，阈值浓度附近薄膜的电阻变化率是高浓度薄膜的五倍。我们介绍的双轴拉伸相比于传统的单轴拉伸，可以使薄膜的应变响应灵敏度提高一个量级。阈值浓度附近薄膜的电阻变化是由于隧道的长度和横截面积的变化，而高浓度薄膜的电阻变化是由于薄膜内部导电通路的变化。双轴拉伸对不同浓度的薄膜会有不同的影响，但提高薄膜灵敏度的结果是一样的。这篇文章为提升GNP/PDMS复合薄膜的应变响应灵敏度以及双轴拉伸在人体运动检测中应用提供了依据。
(a) Resistance of 1 wt. % GNP/PDMS films at different temperatures. (b) Curve between the resistance and the volume concentration of the films varies with temperature.
(a) GF values of GNP films with a concentration of 1 wt. % under different stretching modes. (b) GF values of GNP films with a concentration of 1.5 wt. % under different stretching modes.
16.Ag-Ag2O composite structure with tunable localized surface plasmon resonance as ultrastable, sensitive and cost-effective SERS substrate
超稳定、灵敏及性价比高局域表面等离子共振可调谐Ag-Ag2O复合结构表面增强拉曼基底
Wenfeng Sun, Wenzuo Wei, Qingyou Liu, Tingzhen Yan, Qi Wang, Hui Lin, Chunxian Tao, Dawei Zhang, Ruijin Hong*,Journal of Alloys and Compounds, 2020, 839: 155729【SCI二区】【光学检测材料】
Abstract: Ag-Ag2O composite structure, with fine tunability of localized surface plasmon resonance (LSPR), was fabricated by using Nd:YAG fiber pulsed laser ablation at ambient conditions. In this structure, tunable LSPR wavelength of Ag nanoparticles (NPs) from 384 nm to 486 nm was realized by adjusting the laser power to regulate the oxidation degree and the spacing of Ag NPs. Moreover, Surface enhanced Raman scattering (SERS) was also enhanced due to the LSPR phenomenon. As SERS substrates, Ag-Ag2O composite structure has good stability providing unchanged Raman enhancement signals after 90 days of fabrication due to the protective oxidative layer, i.e. Ag2O shell. This study provides a scalable and facile route to fabricate Ag-Ag2O composite structure and to tune its LSPR properties, which might play a crucial part in the development of plasmonic and other applications.
摘要：在大气环境条件下使用Nd：YAG光纤脉冲激光烧蚀法来制备具有可调局部表面等离子体共振（LSPR）的Ag-Ag2O复合结构。在此结构中，通过调节激光功率从而调节Ag 纳米颗粒的氧化程度和颗粒的间距，实现了Ag纳米颗粒吸收曲线从384 nm至486 nm的峰漂。此外，由于LSPR现象，Ag-Ag2O复合结构的表面增强拉曼散射（SERS）也得到了增强。将其作为SERS衬底，Ag-Ag2O复合结构具有良好的稳定性。同时，由于其外面覆盖的保护性氧化层（即Ag2O壳），使得样品在制造90天后仍然拥有几乎没有衰减的拉曼增强信号。这项研究提供了一种方便且重复性好的方法来制备Ag-Ag2O复合结构，并调节其LSPR特性，这将在等离子和其他应用的开发中起关键作用。
实验过程原理图
(a)不同激光功率下样品的吸收曲线
(b) 不同激光功率下样品的拉曼强度
17.Photocatalytic water splitting properties of Cu2+ exchanged Beta zeolites
铜离子交换beta沸石光解水的研究
Jian Lu, Dawei Zhang*, Hui Lin, Ruijin Hong, Chunxian Tao, Zhaoxia Han and Songlin Zhuang,Nanotechnology, 2020, 31, 14: 145715
【SCI二区】【光催化材料】
Abstract：Photocatalytic water splitting with solar energy is the most promising and friendly hydrogen production method. Efficient and cost-effective photocatalyst is the key to hydrogen production. The Cu dopant has been shown to greatly enhance the photocatalytic activities. In this work, the Cu2+ ions were doped into Beta zeolite powders (Cu-Beta) by the ion exchange method. The hydrogen evolution efficiency of Cu-Beta was much higher than the raw Beta zeolites without Cu loading. After solid phase reaction, the band gap of Cu-Beta reduced from 3.48 eV to less than 2 eV, in result enhancing the optical absorption intensity, especially in the visible region. The best hydrogen evolution efficiency was 102.12 μmol·g-1·h-1 when the treated temperature was 900 ºC (Cu-Beta-900). The temperature of solid phase reaction had important influence on the photocatalytic performance of Cu-Beta, a suitable reaction temperature can greatly improve the photocatalytic performance of Cu-Beta.
摘要：利用太阳能来光催化分解制氢是最有潜力且环保的制氢方式。寻找效率高且廉价的光催化剂是制氢的关键。已有研究表明铜掺杂能极大地增强光催化活性。本文通过离子交换法将Cu2+掺入beta沸石（Cu-Beta）粉末中。Cu-Beta的析氢效率远高于未添加铜的原始beta沸石。固相反应后，Cu-Beta的带隙从3.48eV减小到低于2eV，从而提高了光吸收强度，特别是在可见光区域。当处理温度为900 ºC（Cu-Beta-900）时，最佳的析氢效率为102.12 μmol·g-1·h-1。固相反应温度对Cu-Beta的光催化性能有重要影响，合适的反应温度可以大大提高Cu-Beta的光催化性能。
(a)析氢效率
(b) 光吸收强度
(c)能带结构示意图
18.Effect of alumina addition on the microstructure and luminescence properties of BaAl2O4:Eu2+-Al2O3 green fluorescent composite ceramics fabricated by spark plasma sintering
氧化铝添加对放电等离子烧结BaAl2O4:Eu2+-Al2O3绿色荧光复合陶瓷微观结构和发光性能的影响
Xiaomeng Yin, Hui Lin*, Dawei Zhang, Ruijin Hong, Chunxian Tao, Zhaoxia Han, Ceramics International, 2020, 46: 3801-3810.
【SCI二区】【激光照明材料】
Abstract：BaAl2O4:Eu2+green phosphors were prepared by the solid state reaction method. The structural and optical properties of phosphors with different Eu ions doping concentrations and thermal treatment temperatures were investigated. Then the Ba0.97Al2O4:Eu2+ 0.03 (BAO:Eu2+0.03) phosphor powders were sintered into ceramics by spark plasma sintering (SPS). In addition, different amounts of alumina were added to fabricate composite ceramics, aiming to improving the thermal conductivity and the light extraction efficiency. X-ray diffraction θ-2θ scans showed that hexagonal BaAl2O4 was the only crystalline phase in the BaAl2O4–Al2O3 composite, which implied that an amount of glass phase may be formed. The addition of alumina also has the effect on limiting the grain growth of BaAl2O4. In addition, the amount of pores was obviously reduced in the composite ceramics, which may be attributed to the improved densification brought by the glass phase. The BAO:Eu2+0.03-15w% Al2O3 composite ceramic has the highest luminescence intensity, which was 2.8 times as high as that of the BAO:Eu2+ 0.03 ceramic. And the thermal conductivity of the BAO:Eu2+0.03-15wt% Al2O3 composite ceramics is 1.6 times as high as that of BAO:Eu2+0.03 ceramics. This indicates introduction of alumina can improve the heat removal capability and enhance the luminescence output of the BaAl2O4:Eu2+ fluorescent ceramic.
摘要：通过固相反应法制备了BaAl2O4：Eu2 +绿色荧光粉。研究了不同Eu离子掺杂浓度和热处理温度的荧光粉的结构和光学性质。然后，通过放电等离子体烧结（SPS）将Ba0.97Al2O4：Eu2 + 0.03（BAO：Eu2 + 0.03）荧光粉粉末烧结成陶瓷。另外，添加不同量的氧化铝以制备复合陶瓷，旨在提高导热性和光提取效率。X射线衍射扫描表明，六方相的BaAl2O4是BaAl2O4-Al2O3复合材料中唯一的结晶相，这意味着可能形成了一定数量的玻璃相。氧化铝的添加还具有限制BaAl2O4晶粒生长的作用。另外，复合陶瓷中的孔数量明显减少，这可归因于玻璃相使致密化改善。BAO：Eu2 + 0.03-15w％Al2O3复合陶瓷具有最高的发光强度，是BAO：Eu2 + 0.03陶瓷的2.8倍。 BAO：Eu2 + 0.03-15 wt％Al2O3复合陶瓷的导热系数是BAO：Eu2 + 0.03陶瓷的导热系数的1.6倍。这表明引入氧化铝可以提高BaAl2O4：Eu2 +荧光陶瓷的散热能力并提高其发光输出。
(a) The PL spectra and PLE spectra of BAO:Eu2+0.03-xAl2O3(x = 0 wt%, 10 wt%, 15 wt%, 20 wt%) composites ceramic fabricated by SPS at 1350 °C. Inset: the photograph of the BAO:Eu2+ 0.03-xAl2O3(x = 0 wt%, 10 wt%, 15 wt%, 20 wt%) ceramic samples (from left to right).
在1350℃通过SPS热处理的 BAO:Eu2+0.03-xAl2O3(x = 0 wt%, 10 wt%, 15 wt%, 20 wt%)复合陶瓷的激发和发射光谱（插图：从左到右分别为 BAO:Eu2+0.03-xAl2O3(x = 0 wt%, 10 wt%, 15 wt%, 20 wt%)陶瓷的图片）
(b)Thermally etched cross-sectional SEM images of the fracture surface of (a) BAO:Eu2+0.03ceramic, (b) BAO:Eu2+0.03-10wt% Al2O3composite, (c) BAO:Eu2+0.03-15 wt% Al2O3composite and (d) BAO:Eu2+0.03-20 wt% Al2O3composite.
BAO:Eu2+0.03陶瓷, (b) BAO:Eu2+0.03-10wt% Al2O3陶瓷, (c) BAO:Eu2+0.03-15 wt% Al2O3陶瓷和 (d) BAO:Eu2+0.03-20 wt% Al2O3陶瓷的断面热腐蚀SEM图。
19.White emitting aluminosilicate glass phosphors derived from Dy3+, Ag+ co-exchanged LTA zeolite
以Dy3+, Ag+交换的LTA分子筛转变的白光发射硅铝酸荧光玻璃
Zixin Wang, Hui Lin*, Langjing Xu, Ruijin Hong, Dawei Zhang,Shengming Zhou,Ceramics International,2020,46, 18: 28933-28938
【SCI二区】【激光照明材料】
Abstract: White emitting glass phosphors were derived from the Dy3+, Ag+ co-exchanged LTA zeolite by heat treatment. Attributed to the porous structure and low Si:Al ratio of LTA, analuminosilicate glass phosphor with outstanding thermomechanical and optical properties was obtained at a relatively low melting temperature. Due to the energy transfer from the Ag+ ions to the Dy3+ ions, the emission intensity of the Dy3+, Ag+ co-doped sample (λex=250nm) was improved by 4 times compared with the Dy3+ singly doped sample (λex=388nm). And the chromaticity coordinates moved from the yellow region to the white region. All the results suggested a facile method to fabricate glass phosphors for white light source applications.
摘要：通过对Dy3+、Ag+共交换LTA沸石进行热处理得到了白光发射的荧光玻璃。由于LTA沸石的多孔结构和低硅铝比，可以在较低的熔融温度下获得了具有优异热机械和光学性能的铝硅酸盐荧光玻璃。由于能量从Ag+到Dy3+离子之间的能量传递，Dy3+、Ag+共掺杂样品(λex=250nm)的发射强度比Dy3+单掺杂样品(λex=388nm)提高了4倍。且色度坐标从黄色区域移动到白色区域。所有上述结果表明了本文提出了一种简单有效的直播白光照明用荧光玻璃的方法。
Fig. 3. The optical transmission spectra of pristine glass host, the Dy3+ doped, the Ag+ doped and the Dy3+, Ag+ co-doped glass phosphors, the inset graph gives a photo of the Dy3+, Ag+ co-doped glass phosphors.
Fig. 7. The CIE chromaticity diagram of the emission of the Dy3+ doped and the Dy3+, Ag+ co-doped glass phosphorsunder the 388 nm and 250 nm excitations, respectively.
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