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学者姓名:王大勇
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Abstract :
A photonic-assisted distributed multiple-input and multiple-output (MIMO) chaotic radar is proposed based on multidimensional multiplexing. Reference chaotic (RC) optical signals and echo modulation signals from different remote stations (RSs) are transmitted to the central station (CS) and distinguished using wavelength division multiplexing. Signal-level fusion processing of all RSs' data and adjustment of operating frequency are simultaneously realized. Owing to the quasi-orthogonal waveform multiplexing and non-deterministic characteristics of chaotic signals, high spectrum efficiency and anti-interference capability can be ensured. Three functions, including broadband chaotic signal generation, and frequency up-and down-conversion, are integrated by polarization multiplexing. The radar becomes much more compact by sharing the laser and modulator. A distributed 2 $\times$ 2 MIMO chaotic radar with an effective bandwidth of 6 GHz in Ku-band is established, and the 2-D positions of the targets can be obtained by a back-projection algorithm. The experimental results show that the range and azimuth resolutions are 3.09 and 6.35 cm, respectively, and the average positioning error is less than 0.71 cm. A potential solution of high-precision 2-D positioning is provided for target detection in complex electromagnetic environments.
Keyword :
Optical modulation Optical modulation Radar cross-sections Radar cross-sections Chaotic radar Chaotic radar Frequency conversion Frequency conversion Laser radar Laser radar multidimensional multiplexing multidimensional multiplexing Frequency modulation Frequency modulation Chaotic communication Chaotic communication frequency conversion frequency conversion microwave photonics microwave photonics Optical fibers Optical fibers Frequency division multiplexing Frequency division multiplexing Modulation Modulation Fiber optics Fiber optics
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GB/T 7714 | Zhang, Yu , Zhang, Jing , Wang, Yunxin et al. Photonic-Assisted Distributed MIMO Chaotic Radar Based on Multidimensional Multiplexing [J]. | IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES , 2024 . |
MLA | Zhang, Yu et al. "Photonic-Assisted Distributed MIMO Chaotic Radar Based on Multidimensional Multiplexing" . | IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES (2024) . |
APA | Zhang, Yu , Zhang, Jing , Wang, Yunxin , Liu, Zhe , Wang, Dayong , Zhou, Yuanfen et al. Photonic-Assisted Distributed MIMO Chaotic Radar Based on Multidimensional Multiplexing . | IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES , 2024 . |
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Abstract :
Dual-axis galvanometer is used as a common beam steering component in diverse illumination and imaging approaches. In this paper, we propose an uncorrelated uniform illumination approach based on dual-axis galvanometric scanning. Specially, we analyze the mechanism of galvanometric illumination and elucidate three main factors affecting its uniformity properties. In this illumination module, the laser beam is deflected rapidly by the galvanometer which is driven by triangular voltage signals, and then focused by an f-theta lens to illuminate the object at an equal lateral scanning velocity. This method has lower coherent noise than extended laser illumination, higher brightness than partial coherent illumination and higher uniformity than galvanometric Lissajous trajectory driven by sinusoidal signals.
Keyword :
Uniform illumination Uniform illumination Lissajous scanning Lissajous scanning Galvanometer Galvanometer Speckle suppression Speckle suppression
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GB/T 7714 | Rong, Lu , Zhang, Yuzhe , Ge, Lei et al. Uniformity optimization of galvanometric illumination [J]. | OPTICS AND LASER TECHNOLOGY , 2024 , 181 . |
MLA | Rong, Lu et al. "Uniformity optimization of galvanometric illumination" . | OPTICS AND LASER TECHNOLOGY 181 (2024) . |
APA | Rong, Lu , Zhang, Yuzhe , Ge, Lei , Wan, Min , Li, Jiawen , Liu, Yiming et al. Uniformity optimization of galvanometric illumination . | OPTICS AND LASER TECHNOLOGY , 2024 , 181 . |
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Abstract :
太赫兹波作为一种穿透性强、具有非电离性和惧水性的电磁波,可以穿透多种非金属、非极性介质材料。太赫兹计算层析成像技术基于傅里叶中心切片定理和直线传播模型,通过记录不同投影角度下的强度数据,采用滤波反投影等重建算法获得样品三维吸收系数分布和内外部结构信息分布。随着太赫兹成像器件的不断发展和应用场景的拓展,已发展出多种照明模式、成像光路和重建算法,并已在文物保护、骨密度测量和无损检测领域开展了应用探索。概述太赫兹计算层析技术的基本原理,并从提高重建质量、分辨率和采集效率三方面具体介绍太赫兹计算层析成像技术的最新研究。
Keyword :
照明光场调控 照明光场调控 三维成像 三维成像 太赫兹成像 太赫兹成像 计算层析 计算层析
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GB/T 7714 | 戎路 , 刘乂铭 , 宁冉 et al. 太赫兹计算层析成像研究进展(特邀) [J]. | 激光与光电子学进展 , 2024 , 61 (02) : 207-224 . |
MLA | 戎路 et al. "太赫兹计算层析成像研究进展(特邀)" . | 激光与光电子学进展 61 . 02 (2024) : 207-224 . |
APA | 戎路 , 刘乂铭 , 宁冉 , 赵洁 , 王云新 , 王大勇 . 太赫兹计算层析成像研究进展(特邀) . | 激光与光电子学进展 , 2024 , 61 (02) , 207-224 . |
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Abstract :
For decades, terahertz (THz) microscopic imaging has been limited by the resolution of the system due to the larger wavelength, the power of the source, and the equivalent noise power of the detector, so a lot of research has focused on single-point scanning imaging. With the development of hardware, full-field THz imaging based on high-power continuous-wave THz sources have been developed such as the direct intensity imaging method and lensless coherent imaging. In particular, the THz direct intensity imaging method requires no complicated computational reconstruction, while the high resolution, as a key issue, still needs to be improved. In this paper, the rotating coherent scattering microscopy was applied to THz imaging for the first time. Here, we designed and fabricated a hemisphere lens with high-resistance silicon. The tilted hemisphere lens transformed the incident divergent beam into a plane wave, and the total internal reflection occurred in the planar surface within the hemispherical lens, and generated evanescent waves in the rare medium. At the same time, the sample was placed very close to the plane of the hemispherical lens, so that the sample was illuminated by the evanescent waves. The scattered waves carried high frequency information to the far field, and thus through an objective, the super-resolution imaging was achieved along a single direction. Then, the hemispherical lens was rotated to obtain coherent scattering microscopic images under different evanescent wave illumination angles. Finally, the full-field super-resolution imaging results were obtained through incoherent superposition.
Keyword :
full-field full-field evanescent wave evanescent wave rotating coherent scattering microscopy rotating coherent scattering microscopy terahertz imaging terahertz imaging super-resolution super-resolution
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GB/T 7714 | Ma, Duoxuan , Zhao, Jie , Wang, Dayong et al. Full-Field Super-Resolution Terahertz Imaging Based on Rotating Coherent Scattering Microscopy [J]. | APPLIED SCIENCES-BASEL , 2023 , 13 (2) . |
MLA | Ma, Duoxuan et al. "Full-Field Super-Resolution Terahertz Imaging Based on Rotating Coherent Scattering Microscopy" . | APPLIED SCIENCES-BASEL 13 . 2 (2023) . |
APA | Ma, Duoxuan , Zhao, Jie , Wang, Dayong , Lin, Hao , Rong, Lu , Wang, Yunxin et al. Full-Field Super-Resolution Terahertz Imaging Based on Rotating Coherent Scattering Microscopy . | APPLIED SCIENCES-BASEL , 2023 , 13 (2) . |
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Abstract :
Fourier ptychographic microscopy (FPM) is an effective computational imaging method that incorporates many advantages such as large field of view, high resolution, label-free, and quantitative phase-contrast imaging. Typically, an LED array is used as the illumination source. Due to the small size and narrow spectral width of the LED unit, FPM is usually treated as a coherent imaging system. However, practically, each LED unit is a spatially-extended light source with a certain emitting area, rather than an ideal point source. The ideal point source approximation will decrease the quality of the reconstructed image, to a certain extent. In this paper, the spatial coherence characteristics of FPM system based on LED illumination is analyzed, and it is found that the optical field on the object plane is partially coherent. Thus, the artifacts exist when the coherent transfer function is used as the frequency domain constraint. To address this problem, a Butterworth-weighted transfer function is proposed as the frequency domain constraint in the iterative reconstruction process. The simulation and experimental results demonstrate that this new constraint approach can not only reduce the ringing effect in low-resolution images, but also improve the reconstruction quality due to its following better the actual physical mechanism inherent in FPM. In addition, it may reduce the requirement of the spatial coherence of the illumination source, which has great significance for promoting the application of FPM.
Keyword :
phase retrieval algorithm phase retrieval algorithm Fourier ptychographic microscopy Fourier ptychographic microscopy partially coherent imaging partially coherent imaging Butterworth-weighted transfer function Butterworth-weighted transfer function
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GB/T 7714 | Zhao, Jie , Wang, Dayong , Han, Yaqian et al. Improved reconstruction with Butterworth-weighted transfer function for Fourier ptychographic microscopy [J]. | HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS XII , 2022 , 12318 . |
MLA | Zhao, Jie et al. "Improved reconstruction with Butterworth-weighted transfer function for Fourier ptychographic microscopy" . | HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS XII 12318 (2022) . |
APA | Zhao, Jie , Wang, Dayong , Han, Yaqian , Lin, Shufeng , Wang, Yunxin , Rong, Lu . Improved reconstruction with Butterworth-weighted transfer function for Fourier ptychographic microscopy . | HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS XII , 2022 , 12318 . |
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Abstract :
In the THz band, the spoof surface plasmon polariton (SSP) can limit the light to the designed specific spatial frequency by constructing a sub-wavelength structure on the metal surface. This ability makes it possible to break through the diffraction limit of THz imaging. In this paper, a one- dimensional metal groove structure is used to generate the SSP, and the frequency shift characteristics of the object's spatial spectrum under the excitation of a 2.52THz beam are analyzed. On this basis, a grating-coupling-based SSP excitation structure is designed, which consists of a combined array of subwavelength metal grooves and subwavelength slits with different periods. This structure is used to generate strong intensity and make full use of the incident beam. It is promising for generating illumination beams for terahertz far-field super-resolution imaging of subwavelength-spacing samples.
Keyword :
terahertz terahertz Spoof plasmon Spoof plasmon surface waves surface waves
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GB/T 7714 | Li, Kunlun , Wang, Dayong , Rong, Lu et al. Design and simulation comparison of terahertz surface wave based on grating coupling method [J]. | HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS XII , 2022 , 12318 . |
MLA | Li, Kunlun et al. "Design and simulation comparison of terahertz surface wave based on grating coupling method" . | HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS XII 12318 (2022) . |
APA | Li, Kunlun , Wang, Dayong , Rong, Lu , Zhao, Jie , Lin, Shufeng , Wang, Yunxin et al. Design and simulation comparison of terahertz surface wave based on grating coupling method . | HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS XII , 2022 , 12318 . |
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Abstract :
提出了一种由三维打印技术制作的用于0.3 THz波束调控的二元相位型衍射透镜,可产生轴向焦深为25 mm、腰斑直径为1 mm的太赫兹聚焦波束。将该聚焦波束应用于连续太赫兹波计算机辅助层析成像,不仅将成像分辨率提高到1.5 mm,而且由于扩大了系统景深,提高了成像保真度。这类利用三维打印技术制作的二元衍射元件可有效应用于低频太赫兹波段的光束调控,为太赫兹成像系统的性能优化以及聚焦元件的设计制备提供一种有效途径。
Keyword :
信息光学 信息光学 太赫兹计算机辅助层析 太赫兹计算机辅助层析 三维打印技术 三维打印技术 二元衍射透镜 二元衍射透镜 光束调控 光束调控
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GB/T 7714 | 王大勇 , 宁冉 , 金晓宇 et al. 3D打印衍射元件的高分辨太赫兹计算机辅助层析成像研究(特邀) [J]. | 光子学报 , 2022 , 51 (07) : 113-124 . |
MLA | 王大勇 et al. "3D打印衍射元件的高分辨太赫兹计算机辅助层析成像研究(特邀)" . | 光子学报 51 . 07 (2022) : 113-124 . |
APA | 王大勇 , 宁冉 , 金晓宇 , 戎路 , 赵洁 , 王云新 et al. 3D打印衍射元件的高分辨太赫兹计算机辅助层析成像研究(特邀) . | 光子学报 , 2022 , 51 (07) , 113-124 . |
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Abstract :
In this paper, an iterative denoising phase retrieval method is proposed to solve the twin-image problem in continuous-wave terahertz in-line digital holography. The iterative algorithm is based on the classical error reduction algorithm by adding the positive absorption constraint and a new image denoising for the object field to improve the quality of the reconstructed images. At certain geometrical parameter, the twin-image can be treated as noise superimposed in the object plane. The object field is considered as a complex function affected by the twin-image, and then the denoising process embedded in each iteration is applied to the real and imaginary parts of the object field, respectively. The validity of this approach is demonstrated by the high-quality imaging of samples like the Siemens star and the cicada's wing, which are almost free from the twin-image. Also, the proposed method exhibits good robustness to noises existing in the hologram, and the reconstructed images show better quality compared with other popular phase retrieval methods and denoising algorithm. This work would be helpful to expand the application of continuous-wave terahertz in-line digital holography in biomedical imaging and nondestructive testing.
Keyword :
Phase retrieval Phase retrieval In-line digital holography In-line digital holography Terahertz imaging Terahertz imaging Image denoising Image denoising Twin-image Twin-image
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GB/T 7714 | Jin, Xiaoyu , Zhao, Jie , Wang, Dayong et al. Iterative denoising phase retrieval method for twin-image elimination in continuous-wave terahertz in-line digital holography [J]. | OPTICS AND LASERS IN ENGINEERING , 2022 , 152 . |
MLA | Jin, Xiaoyu et al. "Iterative denoising phase retrieval method for twin-image elimination in continuous-wave terahertz in-line digital holography" . | OPTICS AND LASERS IN ENGINEERING 152 (2022) . |
APA | Jin, Xiaoyu , Zhao, Jie , Wang, Dayong , Rong, Lu , Wang, Yunxin , Healy, John J. et al. Iterative denoising phase retrieval method for twin-image elimination in continuous-wave terahertz in-line digital holography . | OPTICS AND LASERS IN ENGINEERING , 2022 , 152 . |
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Abstract :
本发明涉及一种电光相位调制器射频参数的测量方法与装置,用于解决电光相位调制器的射频参数测量过程中相位不可直接测量以及相位抖动问题,包括激光器、保偏光纤分路器、待测电光相位调制器、相位调节器、保偏光纤耦合器、分光器、光电探测器和MZ干涉环路相位稳定控制电路、矢量网络分析仪。相位调节器用于对光载波相位进行调节,待测电光相位调制器对光载波进行调制,两路信号经耦合后经过分光器分成两束,一束光经光电转换后进入矢量网络分析仪,另一束进入MZ控制电路,与相位调节器构成环路,实现对测量过程中由于光纤长度、温度、环境等的影响引起的相位抖动的补偿及控制,进而更准确地对待测电光相位调制器的射频参数进行测量。
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GB/T 7714 | 王大勇 , 李沛晗 , 王云新 et al. 一种电光相位调制器射频参数的测量方法与装置 : CN202110663236.3[P]. | 2021-06-11 . |
MLA | 王大勇 et al. "一种电光相位调制器射频参数的测量方法与装置" : CN202110663236.3. | 2021-06-11 . |
APA | 王大勇 , 李沛晗 , 王云新 , 杨锋 , 戎路 , 赵洁 . 一种电光相位调制器射频参数的测量方法与装置 : CN202110663236.3. | 2021-06-11 . |
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Abstract :
本发明公开了一种基于线偏振光和条纹反射的表面三维重建方法,当投影设备加载均匀照明图案时,调旋转相机前的线偏振片采集四张偏振图像计算线偏振度;当投影设备投影编码图案时,偏振片方向固定,采集多张经过物体表面面型调制的反射编码图像。信息处理设备配置为采集四张偏振图像,计算反射光线偏振度并分析天顶角分布;采集经过物体表面面型调制的反射编码图像,通过图像处理和解码过程得到相互匹配的投影设备发光点与相机像素点;将偏振分析得到的天顶角分布与入射平面三角形几何约束条件融合,得到物体表面法线信息,并通过对表面梯度积分重建物体面型。本发明消除偏振三维重建中天顶角二义性误差问题,并显著降低硬件成本和操作复杂度。
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GB/T 7714 | 赵洁 , 蔡昂 , 王大勇 et al. 一种基于线偏振光和条纹反射的表面三维重建方法 : CN202110369458.4[P]. | 2021-04-06 . |
MLA | 赵洁 et al. "一种基于线偏振光和条纹反射的表面三维重建方法" : CN202110369458.4. | 2021-04-06 . |
APA | 赵洁 , 蔡昂 , 王大勇 , 戎路 , 王云新 . 一种基于线偏振光和条纹反射的表面三维重建方法 : CN202110369458.4. | 2021-04-06 . |
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