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学者姓名：王大勇
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摘要 ：
本文以离轴菲涅耳数字全息实验为基础,探讨了基于角谱衍射传播方法进行数字全息图重建的成像性能,重点挖掘数值计算背后的物理机理,帮助学生更好地理解所涉及的信息光学知识点。首先,介绍了离轴菲涅耳数字全息图常用两种再现方法的原理,分别是频域滤波方法和空域直接回传方法;然后,利用模拟实验分析了这两种方法在实现成像分辨率和视场方面的特征,把全息理论与仿真现象充分地联系起来,揭示隐藏在数值计算之后的光学原理。本文通过对数字全息图前向和后向传播获取再现像的对比分析,加深对傅里叶变换、衍射传播、频谱滤波等基本物理概念的理解和掌握。
关键词 ：
数字全息 数字全息 全息成像 全息成像 频谱滤波 频谱滤波 角谱衍射传播 角谱衍射传播 离轴菲涅耳光路 离轴菲涅耳光路
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| GB/T 7714 | 赵洁 , 王大勇 , 王云新 et al. 角谱法数值再现离轴菲涅耳数字全息成像的物理机制探讨 [J]. | 物理与工程 , 2021 , 31 (04) : 75-81 . |
| MLA | 赵洁 et al. "角谱法数值再现离轴菲涅耳数字全息成像的物理机制探讨" . | 物理与工程 31 . 04 (2021) : 75-81 . |
| APA | 赵洁 , 王大勇 , 王云新 , 戎路 , 李平雪 . 角谱法数值再现离轴菲涅耳数字全息成像的物理机制探讨 . | 物理与工程 , 2021 , 31 (04) , 75-81 . |
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摘要 ：
光学拍频是大学物理和光学实验教学中的重要内容.由于激光器存在中心波长漂移问题,实验中不易产生可观测的拍频信号.受到微波光子技术中微波波段和光波波段相互作用机理的启发,提出了基于微波频差转换的光学拍频方法.借助强度调制和相位调制将两个频差较小的微波信号调制到同一光载波上,结合光学滤波器获得了两个频差极小的稳定光信号,利用光电探测器实现光学拍频,从仿真和实验两个层面分别获得了可视化的低频拍频信号.该研究为大学物理和光学实验提供了与科学前沿相结合的实验方案,可拓展教学内容和教学深度,有利于培养学生的科学素养.
关键词 ：
光学拍频 光学拍频 实验教学 实验教学 频率变换 频率变换
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| GB/T 7714 | 王云新 , 王大勇 , 杨登才 et al. 基于微波频差转换的光学拍频研究 [J]. | 大学物理 , 2021 , 40 (03) : 43-47 . |
| MLA | 王云新 et al. "基于微波频差转换的光学拍频研究" . | 大学物理 40 . 03 (2021) : 43-47 . |
| APA | 王云新 , 王大勇 , 杨登才 , 李平雪 , 戎路 , 赵洁 . 基于微波频差转换的光学拍频研究 . | 大学物理 , 2021 , 40 (03) , 43-47 . |
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摘要 ：
基于微波频差转换的光学拍频研究
关键词 ：
光学拍频 光学拍频 实验教学 实验教学 频率变换 频率变换
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| GB/T 7714 | 王云新 , 王大勇 , 杨登才 et al. 基于微波频差转换的光学拍频研究 [J]. | 王云新 , 2021 , 40 (3) : 43-47 . |
| MLA | 王云新 et al. "基于微波频差转换的光学拍频研究" . | 王云新 40 . 3 (2021) : 43-47 . |
| APA | 王云新 , 王大勇 , 杨登才 , 李平雪 , 戎路 , 赵洁 et al. 基于微波频差转换的光学拍频研究 . | 王云新 , 2021 , 40 (3) , 43-47 . |
| 导入链接 | NoteExpress RIS BibTex |
摘要 ：
A broadband photonic microwave signal processor based on integrated dual-polarization dual-parallel Mach-Zehnder modulator (DP-DPMZM) is proposed. The processor has a tunable local oscillator (LO) signal, which is generated by the optoelectronic oscillator (OEO) loop in one of the sub-DPMZM with high spectral purity and low phase noise, and its center frequency can be tuned by electronic band-pass filter (EBPF). Using the bias voltage of DP-DPMZM and fiber Bragg grating, the carrier-suppressed single-sideband (CS-SSB) modulation of LO and RF signals can be realized, and the up or down conversion of frequency converter can be realized by adjusting the single bias voltage of DP-DPMZM. Moreover, the power fading caused by dispersion is well compensated with the SSB modulation. The experimental results show that the tunable LO signal of 6-20 GHz is successfully generated, the side mode rejection ratio is as high as 48.4 dB, and the 10 kHz phase noise is 107.6 dBc/Hz at 8 GHz. The spurious rejection ratio of up-down conversion signal is 31.4 dB and 33.6 dB, respectively. © 2021 SPIE
关键词 ：
Bandpass filters Bandpass filters Bias voltage Bias voltage Fiber Bragg gratings Fiber Bragg gratings Light modulators Light modulators Modulation Modulation Optoelectronic devices Optoelectronic devices Phase noise Phase noise
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| GB/T 7714 | Yang, Feng , Wang, Dayong , Wang, Yunxin et al. Broadband photonic microwave signal processor with frequency up/down conversion and tunable OEO [C] . 2021 . |
| MLA | Yang, Feng et al. "Broadband photonic microwave signal processor with frequency up/down conversion and tunable OEO" . (2021) . |
| APA | Yang, Feng , Wang, Dayong , Wang, Yunxin , Yang, Dengcai , Hou, Xueyuan . Broadband photonic microwave signal processor with frequency up/down conversion and tunable OEO . (2021) . |
| 导入链接 | NoteExpress RIS BibTex |
摘要 ：
For a noncooperative target, multiple-dimension detection is required to determine its spatial location. A microwave photonic radar is proposed for simultaneous detection of the distance and direction of targets. At the transmitter, a linear frequency modulation (LFM) signal with a large instantaneous bandwidth was obtained by frequency doubling. Meanwhile, the optical reference signal was supplied. At the receiver, two antennas with a certain baseline length were used to receive the echo signal. The dechirp process and fixed-length cable are combined to decouple the distance and direction and distinguish between the positive and negative directions of a target. Theoretical derivation has already verified that the distance and direction can be resolved simultaneously by dechirping of the echo modulation signal and reference signal. In experiments, an LFM signal with an instantaneous bandwidth of 2 GHz (2-4 GHz) was generated and launched as the detection signal. Targets at different distances with positive and negative angles were detected. The results show that the directional measurement ranges from -72.5 0 to 72.5 degrees, and the error is less than 1.6 degrees. The measured distance was found to be quite similar to the actual distance. The proposed approach can confirm the spatial location of a noncooperative target by combining the detection of both distance and direction. Furthermore, the baseline length need not be less than half the wavelength of the echo signal, and large antennas can be chosen to improve the detection distance and range accuracy. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
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| GB/T 7714 | Wang, Yunxin , Hou, Xueyuan , Li, Tao et al. Simultaneous detection of the distance and direction for a noncooperative target based on the microwave photonic radar [J]. | OPTICS EXPRESS , 2021 , 29 (20) : 31561-31573 . |
| MLA | Wang, Yunxin et al. "Simultaneous detection of the distance and direction for a noncooperative target based on the microwave photonic radar" . | OPTICS EXPRESS 29 . 20 (2021) : 31561-31573 . |
| APA | Wang, Yunxin , Hou, Xueyuan , Li, Tao , He, Ziang , Wang, Dayong , Yang, Feng et al. Simultaneous detection of the distance and direction for a noncooperative target based on the microwave photonic radar . | OPTICS EXPRESS , 2021 , 29 (20) , 31561-31573 . |
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摘要 ：
In the past few decades, the applications of terahertz (THz) spectroscopy and imaging technology have seen significant developments in the fields of biology, medical diagnosis, food safety, and nondestructive testing. Label-free diagnosis of malignant tumours has been obtained and also achieved significant development in THz biomedical imaging. This review mainly presents the research status and prospects of several common continuous-wave (CW) THz medical imaging systems and applications of THz medical imaging in biological tissues. Here, we first introduce the properties of THz waves and how these properties play a role in biomedical imaging. Then, we analyse both the advantages and disadvantages of the CW THz imaging methods and the progress of these methods in THz biomedical imaging in recent ten years. Finally, we summarise the obstacles in the way of the application of THz bio-imaging application technology in clinical detection, which need to be investigated and overcome in the future.
关键词 ：
biomedical imaging biomedical imaging digital holography digital holography ptychography ptychography terahertz computed tomography terahertz computed tomography terahertz imaging terahertz imaging
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| GB/T 7714 | Zhang, Yaya , Wang, Chuting , Huai, Bingxin et al. Continuous-Wave THz Imaging for Biomedical Samples [J]. | APPLIED SCIENCES-BASEL , 2021 , 11 (1) . |
| MLA | Zhang, Yaya et al. "Continuous-Wave THz Imaging for Biomedical Samples" . | APPLIED SCIENCES-BASEL 11 . 1 (2021) . |
| APA | Zhang, Yaya , Wang, Chuting , Huai, Bingxin , Wang, Shiyu , Zhang, Yating , Wang, Dayong et al. Continuous-Wave THz Imaging for Biomedical Samples . | APPLIED SCIENCES-BASEL , 2021 , 11 (1) . |
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摘要 ：
By virtue of its versatile recording geometries, ptychography is a promising full-field lensless phase imaging approach in the prosperous research area of terahertz imaging. In this paper, we propose an extrapolation extended ptychographical iterative engine, named as the EE-PIE reconstruction algorithm, to increase the lateral resolution of terahertz ptychography. A divergent spherical beam is applied to illuminate the object, while diffraction patterns are recorded in the Fresnel region. The signal-to-noise ratio of the diffraction patterns is enhanced under divergent probe illumination, while the size of the diffraction patterns is numerically enlarged by the proposed algorithm. Both the reconstruction quality and the resolution are enhanced without adding to the complexity of the setup or increasing the data acquisition time. The proposed method is experimentally demonstrated using a cluster of phylloclades, a patterned polypropylene plate and a Siemens star target. Compared with the planar illumination, the resolution of the divergent spherical illumination is improved by 2.14 times. On this basis, the extrapolation algorithm further improves the experimental resolution by 1.26 times.
关键词 ：
Divergent illumination Divergent illumination Extrapolation algorithm Extrapolation algorithm Phase imaging Phase imaging Ptychography Ptychography Terahertz imaging Terahertz imaging
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| GB/T 7714 | Rong, Lu , Tan, Fangrui , Wang, Dayong et al. High-resolution terahertz ptychography using divergent illumination and extrapolation algorithm [J]. | OPTICS AND LASERS IN ENGINEERING , 2021 , 147 . |
| MLA | Rong, Lu et al. "High-resolution terahertz ptychography using divergent illumination and extrapolation algorithm" . | OPTICS AND LASERS IN ENGINEERING 147 (2021) . |
| APA | Rong, Lu , Tan, Fangrui , Wang, Dayong , Zhang, Yaya , Li, Kunlun , Zhao, Jie et al. High-resolution terahertz ptychography using divergent illumination and extrapolation algorithm . | OPTICS AND LASERS IN ENGINEERING , 2021 , 147 . |
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摘要 ：
Photonics-Assisted frequency conversion based on cascaded modulators is an effective way to satisfy the requirements of distributed antenna array applications. A filter-free photonic image-rejection down-converter with immunity to dispersion-induced power fading is proposed and demonstrated. The radio frequency (RF) signal from the distributed antenna unit is injected into a dual-drive Mach-Zehnder modulator (DDMZM) through an electrical 90° hybrid coupler (HC), and a single-sideband (SSB) signal is realized. It is then transmitted to the center office by an optical fiber link. At the center office, the modulated RF signal is injected into a dual-polarization dual-parallel MZM (DP-DPMZM) after a polarization controller (PC). Afterwards, an LO signal remodulates it through the Y-DPMZM, and carrier-suppressed SSB modulation is fulfilled via another electrical 90° HC. After the power splitting, quadrature I and Q IF signals can be obtained by a photonics-based continuously adjustable phase shifter. Through a combination of the I/Q IF signals with a low-frequency electrical 90° HC, a photonics image-rejection down-converter based on phase cancellation is realized. Moreover, no optical filter is required; thus, the image-rejection down-converter can work with a large bandwidth. The proposed filter-free photonic image-rejection down-converter is theoretically analyzed and experimentally verified. © 2009-2012 IEEE.
关键词 ：
Antenna arrays Antenna arrays Electric connectors Electric connectors Fading (radio) Fading (radio) Image converters Image converters Modulators Modulators Optical fibers Optical fibers Photonics Photonics Polarization Polarization
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| GB/T 7714 | Wang, Dayong , Yang, Feng , Wang, Yunxin et al. Filter-Free Photonic Image-Rejection Down-Conversion for Distributed Antenna Applications [J]. | IEEE Photonics Journal , 2021 , 13 (2) . |
| MLA | Wang, Dayong et al. "Filter-Free Photonic Image-Rejection Down-Conversion for Distributed Antenna Applications" . | IEEE Photonics Journal 13 . 2 (2021) . |
| APA | Wang, Dayong , Yang, Feng , Wang, Yunxin , Chen, Zhiyu , Yang, Dengcai , Wu, Fuzheng . Filter-Free Photonic Image-Rejection Down-Conversion for Distributed Antenna Applications . | IEEE Photonics Journal , 2021 , 13 (2) . |
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摘要 ：
In the present of microscopic imaging technology, both the large imaging field of view (FOV), and high-resolution are required. The Fourier ptychographic microscopy (FPM) does not need to move the sample and can keep the original FOV unchanged. It can expand the frequency bandwidth and reconstruct high-resolution intensity and phase images by using the angle diversity and synthetic aperture. It has a very important application prospect in the field of biomedical detection. However, the LED, used as the illumination source in the FPM, is an extended light source, and the light emitting unit with a certain size will cause the image blurring. Therefore, a reconstruction algorithm based on Lucy-Richardson (L-R) deconvolution is proposed in this paper. The experimental results show that the proposed algorithm can solve the problem of image blurring in FPM imaging and improve the imaging quality. © 2020 SPIE.
关键词 ：
Light Light Light sources Light sources Imaging techniques Imaging techniques Image enhancement Image enhancement Optical instruments Optical instruments Deconvolution Deconvolution Fourier transforms Fourier transforms Light emission Light emission Synthetic apertures Synthetic apertures
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| GB/T 7714 | Sun, Yan , Wang, Dayong , Wang, Yunxin et al. Improvement of imaging quality of Fourier ptychographic microscopy [C] . 2020 . |
| MLA | Sun, Yan et al. "Improvement of imaging quality of Fourier ptychographic microscopy" . (2020) . |
| APA | Sun, Yan , Wang, Dayong , Wang, Yunxin , Zhao, Jie , Rong, Lu . Improvement of imaging quality of Fourier ptychographic microscopy . (2020) . |
| 导入链接 | NoteExpress RIS BibTex |
摘要 ：
针对连续太赫兹波叠层成像重建算法收敛较为迟滞的问题,提出一种连续太赫兹波双物距叠层成像方法及相关重建算法,使用不同记录距离形成的差异化衍射图幅值作为重建算法记录平面的约束条件,增加了记录平面数据多样性和衍射信息冗余度.仿真结果表明,本方法可以加快算法收敛速率,有效减少迭代次数,提高连续太赫兹波定量相衬成像计算效率.随后构建了基于2.52 THz光泵连续太赫兹激光器的双物距叠层成像实验装置,应用双物距记录方法及改进算法重建获得了聚丙烯基字母图案样品的幅值和相位分布,结果表明改进方法可以减少算法迭代次数,提升计算效率,同时改善相位像重建结果保真度.
关键词 ：
叠层成像 叠层成像 双物距 双物距 太赫兹成像 太赫兹成像 相位复原 相位复原
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| GB/T 7714 | 王大勇 , 李兵 , 戎路 et al. 连续太赫兹波双物距叠层定量相衬成像 [J]. | 物理学报 , 2020 , 69 (02) : 298-307 . |
| MLA | 王大勇 et al. "连续太赫兹波双物距叠层定量相衬成像" . | 物理学报 69 . 02 (2020) : 298-307 . |
| APA | 王大勇 , 李兵 , 戎路 , 赵洁 , 王云新 , 翟长超 . 连续太赫兹波双物距叠层定量相衬成像 . | 物理学报 , 2020 , 69 (02) , 298-307 . |
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