Author Affiliations
Abstract
1 School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2 Zhangjiang Laboratory, Shanghai 201204, China
Spatiotemporal optical vortex (STOV) wavepacket carrying transverse photonic orbital angular momentum (OAM) has been extensively studied in the past few years. In this Letter, we propose and study a novel STOV wavepacket with multiple phase singularities embedded in different space–time domains using analytical and numerical approaches. By tuning different parameters used for designing the wavepacket, it is possible to engineer both the magnitude and orientation of the photonic OAM in space–time. The vectorially controllable OAM will pave new avenues and facilitate applications such as novel optical communication, studying complicated quantum systems, and spin-and-OAM interactions.
spatiotemporal optical vortices photonic orbital angular momentum ultrafast optics Chinese Optics Letters
2023, 21(8): 080003
Author Affiliations
Abstract
1 University of Shanghai for Science and Technology, School of Optical-Electrical and Computer Engineering, Shanghai, China
2 Zhangjiang Laboratory, Shanghai, China
3 University of Shanghai for Science and Technology, Shanghai Key Laboratory of Modern Optical System, Shanghai, China
4 Pusan National University, Department of Physics, Busan, Republic of Korea
Spatiotemporal optical vortex (STOV) pulses can carry transverse orbital angular momentum (OAM) that is perpendicular to the direction of pulse propagation. For a STOV pulse, its spatiotemporal profile can be significantly distorted due to unbalanced dispersive and diffractive phases. This may limit its use in many research applications, where a long interaction length and a tight confinement of the pulse are needed. The first demonstration of STOV pulse propagation through a few-mode optical fiber is presented. Both numerical and experimental analysis on the propagation of STOV pulse through a commercially available SMF-28 standard telecommunication fiber is performed. The spatiotemporal phase feature of the pulse can be well kept after the pulse propagates a few-meter length through the fiber even with bending. Further propagation of the pulse will result in a breakup of its spatiotemporal spiral phase structure due to an excessive amount of modal group delay dispersion. The stable and robust transmission of transverse photonic OAM through optical fiber may open new opportunities for transverse photonic OAM studies in telecommunications, OAM lasers, and nonlinear fiber-optical research.
photonic orbital angular momentum spatiotemporal optical vortices multimode fiber Advanced Photonics
2023, 5(3): 036002
1 中国科学院微电子研究所微电子器件与集成技术重点实验室,北京 100029
2 中国科学院大学,北京 100049
为了抑制传统叉形光栅的高级衍射,提出了一种单一的光学元件,即变栅距叉形光栅,通过适当调节光栅线条的中心位置,有效地抑制了不需要的高级衍射。数值模拟和实验证明,变栅距叉形光栅具有良好的单级衍射特性,可以有效地抑制不需要的高级衍射,与理论预测几乎一致,三级衍射光强可从所需一级衍射光强的24%到弱于背景光强度。然后,分析了最大移动距离、周期和图形面积对抑制高级衍射的影响,同时证实了输出光束具有多拓扑荷的螺旋相位结构。变栅距叉形光栅的高级衍射抑制特性使其在成像、显微和粒子捕捉等方面具有广阔的应用前景。
光栅 光学涡旋 衍射光学 单级衍射 准正弦 光学学报
2022, 42(14): 1405005
Author Affiliations
Abstract
Nanophotonics Research Center, Shenzhen Key Laboratory of Micro-Scale Optical Information Technology & Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
The cylindrical vector beam (CVB) has been extensively studied in recent years, but detection of CVBs with on-chip photonic devices is a challenge. Here, we propose and theoretically study a chiral plasmonic lens structure for CVB detection. The structure illuminated by a CVB can generate single plasmonic focus, whose focal position depends on the incident angle and the polarization order of CVB. Thus, the incident CVB can be detected according to the focal position and incident angle and with a coupling waveguide to avoid the imaging of the whole plasmonic field. It shows great potential in applications including CVB-multiplexing integrated communication systems.
cylindrical vector beam surface plasmon polaritons metasurface optical vortices Chinese Optics Letters
2022, 20(2): 023602
涡旋光束因为携带轨道角动量,在光通信、粒子操纵及量子信息等领域都具有重要的应用前景。目前有很多方法可用于产生涡旋光束,如利用螺旋相位板、模式转换、空间光调制器等。然而,传统的方法需要搭建体积相对较大的光学系统,限制了其在集成光学等领域中的应用。不同于传统方法中通过传输效应来获得相位变化,超表面可以通过纳米结构使入射光产生相位突变,在纳米尺度上独立控制动态或几何相位以产生涡旋。超表面具有强大光控制能力的同时,还具有体积小、易于集成等特点,因此成为了产生涡旋光的理想方法。文中在介绍产生涡旋光束基本原理的基础上,回顾了近年来利用超表面产生涡旋光束的研究进展。首先介绍了利用动力学相位、Pancharatnam-Berry (P-B)相位以及混合相位产生光学涡旋的方法。随后,对利用全息与编码超表面产生涡旋及通过多路复用产生多个涡旋等不同方法进行了综述。最后,对基于超表面产生涡旋的一些亟待解决的问题和应用前景作了简单总结与讨论。
光学涡旋 轨道角动量 超表面 产生方法 optical vortices orbital angular momentum metasurface generation methods 红外与激光工程
2021, 50(9): 20210283
厦门大学 电子科学与技术学院,福建 厦门 361005
涡旋光在光通信、量子纠缠、新的非线性光学效应、微纳机械加工、超分辨成像和光镊等领域具有重要的应用价值。涡旋光应用的前提条件是高质量涡旋光束的产生,将缺陷镜技术和固体激光谐振腔技术结合起来研究,对直接产生高光束质量、高稳定性和大拓扑荷数(高阶)的涡旋激光具有明显的优势。当前,该项技术多是用在简单的两镜线性腔中,且以连续波涡旋激光为主。文中使用紫外皮秒脉冲激光器制备了点缺陷镜,并采用LD端面泵浦Nd:YVO4晶体作为激光实验平台,构造了V型激光谐振腔,首次实现了复杂谐振腔内直接产生高阶涡旋激光输出。当吸收功率为11.46 W时,获得了最高输出功率为2.69 W的三阶涡旋激光,斜效率达到23.6%;进一步调节谐振腔及点缺陷尺寸,最高获得了13阶涡旋激光输出。该研究表明缺陷镜技术也可以用于复杂结构激光谐振腔,直接产生高阶涡旋激光,从而为其他运行模式(如调Q和锁模)的高阶涡旋激光研究提供了一定的依据。
全固态激光器 光学涡旋 缺陷镜 V型折叠腔 all-solid-state laser optical vortices defect mirror V-type folded cavity 红外与激光工程
2021, 50(9): 20210408
1 中国电子科技集团公司第三十八研究所, 安徽 合肥 230093
2 中国科学技术大学附属第一医院, 安徽 合肥 230036
3 上海大学通信与信息工程学院, 上海 200444
提出一种基于光学亮环晶格进行空间光信息编码通信的方法。基于面向目标的计算全息术,生成4种简单模式的光学亮环晶格对应的计算全息图,并将其加载在反射式空间光调制器(SLM)上,SLM调制入射光,直接重建4种简单模式的光学亮环晶格。4种光学亮环晶格模式对应4个不同的四进制数,易于识别,通过光学亮环晶格模式的组合完成一幅32 pixel×56 pixel的256阶灰度图的编码与空间传输。距离发射端2 m处的电荷耦合器件(CCD)接收光学亮环晶格图像并通过计算机对数据进行解码,可以在部分干扰情况下,无差错地恢复原始图像信息。在此基础上,实验拓展单个光学亮环晶格至2×2和4×4阵列,传输效率和系统容量提升了4倍和16倍。本研究成果为光学亮环晶格的编码通信研究提供了理论和实验依据。
光通信 光学涡旋 拓扑电荷数 光学亮环晶格 计算全息图 编码 光学学报
2020, 40(11): 1106002
Author Affiliations
Abstract
1 School of Physics and Key Laboratory of Weak-Light Nonlinear Photonics, Nankai University, Tianjin 300071, China
2 National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
In free-space or in optical fibers, orbital angular momentum (OAM) multiplexing for information transmission has been greatly developed. The light sources used were well coherent communication bands, and the fibers used were customized. Here, we use an 810 nm femtosecond laser to generate optical vortices carrying OAM and then feed them into two kinds of commercial step-index few-mode fibers to explore the transmission characteristics of OAM modes. We also propose a method without multiple-input multiple-output digital signal processing to identify the input OAMs. It is of great guiding significance for high-dimensional quantum information experiments via the OAMs as a degree of freedom, using the light generated by the spontaneous parametric down-conversion as the source and the commercial fibers for information transmission.
060.2310 Fiber optics 050.4865 Optical vortices 080.4865 Optical vortices Chinese Optics Letters
2019, 17(12): 120601