Author Affiliations
Abstract
1 School of Physical Science and Technology, Soochow University, Suzhou 215006, China
2 School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
3 Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China
4 Shandong Joint Research Center of Light Manipulation Science and Photonics Integrated Chip of East China Normal University and Shandong Normal University, East China Normal University, Shanghai 200241, China
5 e-mail: xylu@suda.edu.cn
6 e-mail: yangjian_cai@163.com
7 e-mail: zhaochengliang@suda.edu.cn
Fractional vortex beams exhibit a higher degree of modulation dimensions than conventional vortices, thus inheriting superior anti-turbulent transmission properties through the incorporation of additional coherence modulation. However, aliasing the mixed modes induced by coherence degradation makes the quantitative measurement of the topological charge in fractional vortex beams challenging. In this study, a coherence phase spectrum was introduced, and experimental demonstrations to quantitatively determine the fractional topological charge of partially coherent fractional vortex beams were performed. By leveraging the four-dimensional measurement of a partially coherent light field, the source coherence function was inversely reconstructed, and fractional topological charges were determined with high precision by extracting the phase spectrum of the coherence function. Laguerre–Gaussian, elliptical Gaussian, and plane-wave-fraction vortex beams with various degrees of coherence were used to demonstrate measurement precision. The proposed method is applicable to X-rays and electron vortices. It has potential applications in optical encryption, high-capacity optical communication, and quantum entanglement.
Photonics Research
2024, 12(1): 33
1 苏州大学物理科学与技术学院, 江苏 苏州 215006
2 山东师范大学物理与电子科学学院, 山东 济南 250358
3 山东省光场调控工程技术中心, 山东省光学与光子器件技术重点实验室, 山东 济南 250358
涡旋光场是一类具有螺旋型波前的特殊结构光场, 因其携带相位奇点、轨道角动量以及拥有中央暗核结构等物理特性, 被广泛应用于光学微操纵、大容量光通信、超分辨成像等领域。通过对涡旋光场传统的物理维度 (振幅、偏振、频率) 进行调控, 可以得到模式更加丰富、应用领域更广泛的新型涡旋光场。此外, 涡旋光场还有一个非常重要的调控维度, 即相干性。近年来, 研究人员通过对涡旋光场的相干性进行调控得到了一类新型涡旋光场, 即部分相干涡旋光场。相比于完全相干涡旋光场, 部分相干涡旋光场在某些领域更具优势, 如具有较高的抗湍流大气干扰性、更丰富的光束整形、更高的自修复能力和更强的微粒捕获能力等。本综述介绍 了近年来整数阶和分数阶涡旋光场相干性调控方面的研究进展, 重点对部分相干涡旋光场的理论模型、产生方法、传输特性、拓扑荷测量、应用等方面进行了详细阐述。
物理光学 奇点光学 涡旋光场 相干调控 部分相干 拓扑荷测量 physical optics singularity optics vortex field coherence modulation partially coherent topological charge measurement
1 苏州大学物理科学与技术学院, 江苏 苏州 215006
2 山东师范大学物理与电子学院, 山东 济南 250014
3 山东省光场调控工程技术中心, 山东省光学与光子器件技术重点实验室, 山东 济南 250014
相位恢复技术在材料科学、生物医学、天文学等领域有着广泛的应用,不同的相位恢复技术及应用领域,需要用到不同的光源。光源的波长、相干性以及能量等参数都会影响最终的相位恢复效果。在以往的研究中,就空间相干性而言,往往将光源当作完全相干光处理,但是在实际应用中,X射线、电子束等光源都是部分相干光,且完全相干光经过介质时其空间相干性也会降低,因此,如何在部分相干照明下恢复物体正确的相位信息尤为重要。本文概述了空间部分相干照明下相位恢复技术的研究背景及研究进展,重点介绍了常用的几种相位恢复方法:模式分解法、强度传输方程、微扰法以及焦移法等,并对这些方法的优劣进行了对比分析。此外,还概述了微扰法相位恢复技术在特殊关联部分相干光场测量及部分相干涡旋光束拓扑荷数测量中的应用。
相干光学 相位恢复技术 部分相干光 相位信息
1 School of Physical Science and Technology, Soochow University, Suzhou 215006, China
2 Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
3 College of Physics and Electronic Engineering, Heze University, Heze 274015, China
Frontiers of Optoelectronics
2019, 12(3): 229–248
Author Affiliations
Abstract
1 Soochow University, School of Physical Science and Technology, Suzhou, China
2 Delft University of Technology, Optics Research Group, Delft, Netherlands
3 Shandong Normal University, School of Physics and Electronics, Center of Light Manipulation and Application, Jinan, China
We propose and experimentally demonstrate a noniterative diffractive imaging method for reconstructing the complex-valued transmission function of an object illuminated by spatially partially coherent light from the far-field diffraction pattern. Our method is based on a pinhole array mask, which is specially designed such that the correlation function in the mask plane can be obtained directly by inverse Fourier transforming the diffraction pattern. Compared to the traditional iterative diffractive imaging methods using spatially partially coherent illumination, our method is noniterative and robust to the degradation of the spatial coherence of the illumination. In addition to diffractive imaging, the proposed method can also be applied to spatial coherence property characterization, e.g., free-space optical communication and optical coherence singularity measurement.
partial coherence coherent diffractive imaging noniterative method pinhole array mask Advanced Photonics
2019, 1(1): 016005
Author Affiliations
Abstract
1 College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
2 Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
It is known that one can determine the mode orders (i.e., the azimuthal order and radial order) of a partially coherent LGpl beam (i.e., a partially coherent vortex beam) based on the measurement of the cross-correlation function (CCF) and the double correlation function (DCF) together. The technique for measuring the CCF is known. In this Letter, we propose a method for measuring the DCF. Based on the proposed method, the determination of the mode orders of a partially coherent LGpl beam is demonstrated experimentally.
030.1670 Coherent optical effects 050.4865 Optical vortices 350.5500 Propagation Chinese Optics Letters
2017, 15(3): 030002
Author Affiliations
Abstract
1 Optical Institute, Physics Department, Zhejiang University, Hangzhou 310027, China
2 School of Management, Zhejiang University, Hangzhou 310058, China
The material dispersion of a tapered fiber is described by Sellmeier's equation. The dependence of refractive index on wavelength and doping concentration is discussed. A He-Ne laser with the output wavelength of 632.8 nm is used in the experiment. When the cutoff frequency of the fiber is less than the laser frequency, the guiding modes of a single-mode fiber (at 1550 nm) are investigated. The results show that the original single-mode fiber becomes a multi-mode waveguide. The propagation and mode coupling of the light in the taper region are analyzed. By controlling the taper end size of the fiber, the unique tapered fiber can convert a multi-mode beam into a single-mode one.
锥形光纤 色散 场分布 060.2310 Fiber optics 060.2430 Fibers, single-mode 140.3300 Laser beam shaping Chinese Optics Letters
2009, 7(9): 771
就涡旋光束和光学涡旋的基本特征和原理进行了概述,对其产生、传播及应用进行了介绍。对涡旋光束和光学涡旋的研究动态进行了叙述,并对其未来的研究和应用前景进行了展望。
涡旋光束 光学涡旋 相位奇异性 角动量 螺旋相位 光学操控
