Author Affiliations
Abstract
1 Anhui Province Key Laboratory of Aerospace Structural Parts Forming Technology and Equipment, Institute of Industry and Equipment Technology, Hefei University of Technology, Hefei 230009, China
2 Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
3 Hefei National Laboratory for Physical Sciences at the Microscale and CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
A ring-shaped focus, such as a focused vortex beam, has played an important role in microfabrication and optical tweezers. The shape and diameter of the ring-shaped focus can be easily adjusted by the topological charge of the vortex. However, the flow energy is also related to the topological charge, making the individual control of diameter and flow energy of the vortex beam impossible. Meanwhile, the shape of the focus of the vortex beam remains in the hollow ring. Expanding the shape of focus of structural light broadens the applications of the vortex beam in the field of microfabrication. Here, we proposed a ring-shaped focus with controllable gaps by multiplexing the vortex beam and annular beam. The multiplexed beam has several advantages, such as the diameter and flow energy of the focal point can be individually controlled and are not affected by the zero-order beam, and the gap size and position are controllable.
microfabrication femtosecond laser structural beams microring Chinese Optics Letters
2022, 20(2): 023801
西北核技术研究所, 高功率微波技术重点实验室, 西安 710024
基于真空二极管设计了一种X波段大功率微波检波器,该检波器主要由真空二极管、BJ-100波导、调谐螺栓、低通滤波器和直流电源组成,其工作频率可根据需要在8.6~9.8 GHz范围内调谐。重点阐述该型大功率微波检波器的结构设计、实验室标定及辐射场测量实验结果,研究了不同脉宽和不同灯丝电压与检波特性的依赖关系。实验结果表明: 该型检波器具有承受微波脉冲功率高(大于7 kW)、响应快(响应时间小于2.0 ns)、动态范围大、输出信号幅度高(可达数十V)、不需要同步信号等特点,适用于在高功率微波干扰环境下的单次和高重复频率脉冲功率测量。
高功率微波 真空二极管 微波检波器 功率测量 high power microwave vacuum diode microwave power sensor power measurement 强激光与粒子束
2014, 26(9): 093002
超宽谱短电磁脉冲的频谱可覆盖GPS工作频带，对GPS接收机的正常工作存在干扰威胁。从理论分析、数值仿真和实验方面研究了高重频超宽谱短电磁脉冲对GPS接收机干扰效果与脉冲参数之间的依赖关系。结果表明：若脉冲重复频率整数倍能落入GPS接收机工作频带内，高重频超宽谱短电磁脉冲对GPS接收机干扰效果较强，且达到相同干扰效果时所需脉冲幅值随重频增大而等比例减小，即脉冲幅值与重频乘积保持为常数；若重频整数倍偏离GPS接收机工作频带，高重频超宽谱短电磁脉冲对GPS接收机干扰效果不明显。
干扰 超宽谱 脉冲重复频率 GPS GPS interference ultra-wideband pulse repetition frequency 强激光与粒子束
2014, 26(3): 033006
Author Affiliations
Abstract
1 The Key Laboratory of Optoelectronic Information Science and Technology, Ministry of Education of China, Institute of Modern Optics, Nankai University, Tianjin 300071, China
2 Nankai University Affiliated Hospital, Tianjin 300121, China
An efficient and inexpensive method that uses a glass plate mounted onto a motorized rotating stage as a beam-steering device for the generation of dynamic optical traps is reported. Force analysis reveals that there are drag and trapping forces imposed on the bead in the opposite directions, respectively, in a viscous medium. The trapped bead will be rotated following the beam’s motion before it reaches the critical escape velocity when the drag force is equal to the optical trapping force. The equilibrium condition facilitates the experimental measurement of the drag force with potential extensions to the determination of the viscosity of the medium or the refractive index of the bead. The proposed technique can easily be integrated into conventional optical microscopic systems with minimum modifications.
光镊 动态转动光束 临界逃逸速度 120.4820 Optical systems 350.4855 Optical tweezers or optical manipulation 170.4520 Optical confinement and manipulation Chinese Optics Letters
2011, 9(3): 031201
