Author Affiliations
Abstract
1 College of Physics and Electronic Information, Dezhou University, Dezhou 253023, China
2 College of Physics and Electronics, Shandong Normal University, Jinan 250014, China
3 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
4 Shandong Key Laboratory of Biophysics, Dezhou University, Dezhou 253023, China
In this Letter, we fabricate integrated metasurface of encoded dynamic phases and experimentally generate nonconventional Kagome-type lattices of no-second-order phase vortices. The thin metasurface acts analogous to an integration of three conventional optical elements, i.e., six pinholes located at the vertices of two concentric regular triangles of size ratio 1:2, six transparent discs of different thicknesses to introduce a total phase shift difference of , and a Fourier lens with a focal length in the micro-scale. A Kagome lattice with the required vortex distribution is realized at the “focal” plane of the metasurface under illumination of the plane wave.
Kagome lattice metasurface phase modulation Chinese Optics Letters
2020, 18(1): 012201
1 山东大学 控制科学与工程学院， 山东 济南 250061
2 山东大学 信息科学与工程学院， 山东 济南 250100
3 德州学院 物理系， 山东 德州 253023
利用800 nm钛蓝宝石飞秒激光器制备了长周期光纤光栅，并实验验证了长周期光纤光栅的高温特性。基于摄像头和电动位移平台设计了激光精确对准光纤纤芯的方案；以计算机控制1.3 mW飞秒激光，使用逐点曝光法在未经载氢处理的光纤上刻写了长周期光纤光栅，实验显示该光栅在1 200~1 700 nm波段的主谐振峰值可达-17 dB。利用高温箱对长周期光纤光栅进行高温传感特性实验，在300~800 ℃得到的主谐振峰温度响应灵敏度为0.056 nm/℃，线性度为0.992。实验结果表明，提出的以800 nm钛蓝宝石飞秒激光器制备长周期光纤光栅的方法稳定可靠，写制的光栅在高温环境下变化均匀，不易退化，响应特性良好，适用于高温检测。
长周期光纤光栅 飞秒激光 光栅制备 高温传感 long period fiber grating femtosecond laser grating inscription high-temperature sensing
Author Affiliations
Abstract
Department of Physics, Dezhou University, Dezhou 2530232 College of Physics and Electronics, Shandong Normal University, Ji'nan 2500143 Qingdao 53rd middle school, Qingdao 266034
We propose a diode end-pumped passively mode-locked Nd:Gd0.42Y0.58VO4 (Nd:GdYVO4 laser at 1064 nm using a GaAs absorber grown at low temperature as the output coupler. Stable continuous-wave (CW) mode locking with a 5.1-ps pulse duration at a repetition rate of 113 MHz is obtained. The maximum average output power is 2.29 W at the incident pump power of 12 W with the slope efficiency of about 24.8%.
Nd:Gd0.42Y0.58VO4 晶体 低温生长GaAs 连续锁模 半导体激光端面泵浦激光器 140.0140 Lasers and laser optics 140.2020 Diode lasers Chinese Optics Letters
2008, 6(5): 361
山东师范大学物理与电子科学学院, 山东 济南 250014
建立了激光晶体的热传导模型,通过求解泊松方程,得到激光晶体内温度和温度场分布,计算了由端面形变引起的光程差(OPD)和总的光程差,得到不同抽运功率下的热焦距,并通过实验进行了验证,实验结果与理论计算基本一致。当抽运功率为10 W,抽运光斑半径320 μm时,Nd:YVO4激光晶体端面形变引起的光程差占总的光程差的45%。抽运功率为24 W时,晶体热焦距为65.8 mm。提出激光晶体端面腔镜会加重激光晶体热透镜效应的结论。研究表明,对于大功率全固态激光器,由晶体端面形变引起的光程差对晶体热透镜效应有较大影响。对提高激光器的稳定性、研究晶体的热效应提供了理论依据。
激光技术 固体激光器 泊松方程 端面形变 光程差 热焦距
