1 云南师范大学物理与电子信息学院, 云南 昆明 650500
2 昆明医科大学第一附属医院, 云南 昆明650032
波导带通滤波器是大功率微波滤波的重要器件, 为5G通信基站大功率微波传输提供了可能。基于光子晶体的频率带隙特性, 把二维圆柱型光子晶体引入矩形波导中, 设计了一款应用于5G通信的二维圆柱型光子晶体波导带通滤波器, 仿真研究了该滤波器的滤波特性, 以及引入点缺陷、线缺陷时滤波器的性能变化。二维光子晶体结构在矩形波导中在3~7 GHz之间显现了带通特性, 仿真结果表明, 该滤波器可以应用于5G通信n77、n78、n79频段。
光子晶体 波导 带通滤波器 5G通信 设计 photonic crystal waveguide bandpass filter 5G communication design
Author Affiliations
Abstract
1 School of Electronic and Information Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China
2 School of Materials Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China
3 College of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052, China
4 e-mail: yaoyong@hit.edu.cn
We reported on the generation of the dual-wavelength rectangular pulse in an erbium-doped fiber laser (EDFL) with a topological insulator saturable absorber. The rectangular pulse could be stably initiated with pulse width from 13.62 to 25.16 ns and fundamental repetition rate of 3.54 MHz by properly adjusting the pump power and the polarization state. In addition, we verified that the pulse shape of the dual-wavelength rectangular pulse can be affected by the total net cavity dispersion in the fiber laser. Furthermore, by properly rotating the polarization controllers, the harmonic mode-locking operation of the dual-wavelength rectangular pulse was also obtained. The dual-wavelength rectangular pulse EDFL would benefit some potential applications, such as spectroscopy, biomedicine, and sensing research.
Mode-locked lasers Nonlinear optics, fibers Nonlinear optical materials Photonics Research
2015, 3(3): 03000094
1 北京工业大学 先进制造技术重点实验室，北京 100022
2 北京科技大学 机械工程学院，北京 100083
3 北京京东方股份有限公司，北京 100016
4 唐山学院 机械系，唐山 063000
工件表面的激光强化效果直接取决于扫描过程中的热循环规律，为获得理想的淬硬层深及显微硬度分布，必须对激光作用的温度分布形态做出精确解析。采用有限单元法可以对各种工艺参数的变化对激光强化温度场的影响加以探讨，并辅以红外测温实验结果进行验证。结果表明，激光强化可以有效改善金属材料表面的组织性能，而工艺参数的改变对于热循环规律有着显著影响。
激光技术 激光强化 热循环 温度场 红外 laser technique laser strengthening thermal circulation temperature field infrared
