Author Affiliations
Abstract
1 Zhejiang University, School of Physics, Zhejiang Province Key Laboratory of Quantum Technology and Device, Hangzhou, China
2 Zhejiang University, Center for Data Science, Hangzhou, China
Holographic imaging poses significant challenges when facing real-time disturbances introduced by dynamic environments. The existing deep-learning methods for holographic imaging often depend solely on the specific condition based on the given data distributions, thus hindering their generalization across multiple scenes. One critical problem is how to guarantee the alignment between any given downstream tasks and pretrained models. We analyze the physical mechanism of image degradation caused by turbulence and innovatively propose a swin transformer-based method, termed train-with-coherence-swin (TWC-Swin) transformer, which uses spatial coherence (SC) as an adaptable physical prior information to precisely align image restoration tasks in the arbitrary turbulent scene. The light-processing system (LPR) we designed enables manipulation of SC and simulation of any turbulence. Qualitative and quantitative evaluations demonstrate that the TWC-Swin method presents superiority over traditional convolution frameworks and realizes image restoration under various turbulences, which suggests its robustness, powerful generalization capabilities, and adaptability to unknown environments. Our research reveals the significance of physical prior information in the optical intersection and provides an effective solution for model-to-tasks alignment schemes, which will help to unlock the full potential of deep learning for all-weather optical imaging across terrestrial, marine, and aerial domains.
spatial coherence holographic imaging turbulence image restoration deep learning 
Advanced Photonics
2023, 5(6): 066003
Author Affiliations
Abstract
Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Hangzhou 310058, China
Optical geometrical transformation is a novel and powerful tool to switch orbital angular momentum (OAM) states in modern optics. We demonstrate a scheme to operate multiplication and division in OAM by Fermat’s spiral transformation. The characteristics of the output beams in the case of integer and fraction OAM operations are presented in detail. Additionally, the power weight of the output OAM modes and the interference patterns of the output beams are reported to confirm the expected ability of OAM mode conversion by Fermat’s spiral transformation. We further investigate the evolution of OAM beams in operations theoretically and experimentally. This work provides a practical way to perform an optical transformation mapping on OAM beams. It can find application in optical communications with larger OAM mode numbers as well as quantum information in high-dimensional systems.
Photonics Research
2023, 11(2): 165
Author Affiliations
Abstract
Zhejiang Provincial Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, China
We introduce a new class of partially coherent asymmetric array beams. When the beam propagates, the spectral density of each lobe and the corresponding degree of coherence have rotating behavior. Especially, not only can array-like lattices revolve arbitrarily, but also they can move freely by controlling transverse plane shifts. Furthermore, we have generated this kind of beam experimentally, and the experimental phenomena are consistent with the numerical simulation results. Such a rotating beam with free movement and revolution may broaden the way for optical applications. More importantly, it inspires further studies in the field of asymmetric coherence gratings and lattices.
partial coherence asymmetric array beams rotating behavior transverse plane shifts free movement and revolution 
Chinese Optics Letters
2022, 20(2): 022602
王涛 1,2,*赵道木 1
作者单位
摘要
1 浙江大学物理系, 浙江 杭州 310027
2 四川师范大学物理与电子工程学院, 四川 成都 610068
光波经介质散射后的远场光学特性,包括光谱强度、光谱相干度以及光谱偏振度等,与散射介质的结构特征密切相关。近年来,光波弱散射现象的研究取得了较大进展,一方面,研究人员将散射体推广到各种介质,包括各向异性介质、半软边介质、椭球形介质等;另一方面,研究人员将入射光波推广到各种常见的光束,如随机电磁光波、平面波脉冲光束、非匀幅光束等。介绍了关于光波弱散射问题的主要研究成果,包括光波散射过程中的光谱变化现象、相干性变化现象、等价理论、互易关系以及光波散射逆问题等。
物理光学 光波散射 光谱变化 光谱相干性 等价理论 互易关系 逆问题 
光学学报
2016, 36(10): 1026006
Author Affiliations
Abstract
1 Department of Physics, Sichuan Normal University, Chengdu 610068, China
2 Department of Physics, Zhejiang University, Hangzhou 310027, China
The far-zone scattered spectral density of a light wave on the scattering from a collection of particles is investigated, and the relationship between the character of the collection and the distribution of the scattered spectral density is discussed. It is shown that both the number of particles and their locations in the collection play roles in the distribution of the far-zone scattered spectral density. This phenomenon may provide a potential method to reconstruct the structure character of a collection of particles from measurements of the far-zone scattered spectral density.
290.2558 Forward scattering 290.5850 Scattering, particles 
Chinese Optics Letters
2015, 13(10): 102901
作者单位
摘要
浙江大学物理系, 浙江 杭州 310027
偏振光学中被广泛应用的Stokes参量已由单点函数扩展到两点函数,并用于研究随机电磁光束的偏振度和相干度问题。广义Stokes参量成为部分相干光学研究的一个新的热点,正逐步成为与交叉光谱密度矩阵等价的研究方法。基于广义衍射积分公式,导出了广义Stokes参量通过轴对称或非对称光学系统的传输方程,并应用Stokes参量研究随机电磁光束中完全偏振部分的偏振态(包括偏振度、偏振椭圆的方位角、椭率角)变化问题。分析了随机电磁高斯-谢尔模型光束通过双焦系统的偏振态变化规律。
相干光学 偏振态 张量方法 随机电磁光束 
中国激光
2009, 36(9): 2332
作者单位
摘要
浙江大学物理系, 浙江 杭州 310027
研究发现完全非偏振随机电磁光束和完全偏振随机电磁光束在自由空间传输的过程中, 只有在特定的条件下才会保持其光谱偏振度不变, 即保持其完全非偏振或完全偏振的状态; 否则随着传输距离的增加, 这两类光束都将转化为部分偏振光束。通过数值计算和理论分析得到了以下结论:随机电磁光束在自由空间传输的过程中光谱偏振度的变化分别取决于决定光场相互关联的参数δ, 以及决定光源强度分布的参数σ。
相干光学 偏振度不变性 相干偏振统一理论 随机电磁光束 
光学学报
2009, 29(s1): 79
作者单位
摘要
1 湖州师范学院物理系, 浙江 湖州 313000
2 浙江大学物理系, 浙江 杭州 310027
提出了矢量可控空心光束概念, 可控空心光束可以很好地描写中心光强不完全为零的圆对称空心光束, 具有可用多个参量来控制中央暗斑尺寸、形式简单易于分析、其传输变换特性更接近于实际等特点。利用矢量瑞利-索末菲衍射积分公式, 导出了矢量可控空心光束的非傍轴传输解析公式, 从所得结果可退化得到傍轴近似结果。利用导出的公式计算分析了矢量可控空心光束在自由空间的非傍轴传输特性, 并与傍轴结果进行了比较分析。结果表明矢量可控空心光束在近场很好地保持其空心光场分布特性; 参量f和传输距离决定了矢量可控空心光束的非傍轴特性。
物理光学 矢量可控空心光束 非傍轴传输 衍射积分 
光学学报
2009, 29(6): 1675
Author Affiliations
Abstract
1 Department of Physics, Zhejiang University, Hangzhou 310027
2 Research Center of Laser Fusion, CAEP, Mianyang 621900
Based on the principle that a rectangular function can be expanded into a sum of complex Gaussian functions with finite numbers, propagation characteristics of a Gaussian beam or a plane wave passing through apertured fractional Fourier transforming systems are analyzed and corresponding analytical formulae are obtained. Analytical formulae in different fractional orders are numerically simulated and compared with the diffraction integral formulae, the applicable range and exactness of analytical formulae are confirmed. It is shown that the calculating speed of using the obtained approximate analytical formulae, is several hundred times faster than that of using diffraction integral directly. Meanwhile, by using analytical formulae the effect of different aperture sizes on Gaussian beam propagation characteristics is numerically simulated, it is shown that the diffraction effect can be neglected when the aperture size is 5 times larger than the beam waist size.
070.2590 Fourier transforms 140.3300 laser beam shaping 050.1220 apertures 
Chinese Optics Letters
2004, 2(4): 04206

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