强激光与粒子束
2022, 34(1): 011010
Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
2 National Innovation Institute of Defense Technology, Academy of Military Sciences China, Beijing 100071, China
3 Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
4 e-mail: hzhang@szu.edu.cn
The year 2019 marks the 10th anniversary of the first report of ultrafast fiber laser mode-locked by graphene. This result has had an important impact on ultrafast laser optics and continues to offer new horizons. Herein, we mainly review the linear and nonlinear photonic properties of two-dimensional (2D) materials, as well as their nonlinear applications in efficient passive mode-locking devices and ultrafast fiber lasers. Initial works and significant progress in this field, as well as new insights and challenges of 2D materials for ultrafast fiber lasers, are reviewed and analyzed.
Photonics Research
2020, 8(1): 01000078
Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
2 State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073,China
3 National Innovation Institute of Defense Technology, Academy of Military Sciences PLA China, Beijing 100010, China
4 State Key Laboratory of Laser Interaction with Matter, Northwest Institute of Nuclear Technology, Xi’an 710024, China
The layered MoS2 has recently attracted significant attention for its excellent nonlinear optical properties. Here, the ultrafast nonlinear optical (NLO) absorption and excited carrier dynamics of layered MoS2 (monolayer, 3-4 layers, and 6-8 layers) are investigated via Z-scan and transient absorption spectra. Our experimental results reveal that NLO absorption coefficients of these MoS2 increase from -27 × 103cm/GW to -11 × 103cm/GW with more layers at 400-nm laserexcitation, while the values decrease from 2.0 × 103 cm/GW to 0.8 × 103 cm/GW at 800 nm. In addition, at high pump fluence, when the NLO response occurs, the results show that not only the reformation of the excitonic bands, but also the recovery time of NLO response decreases from 150 ps to 100 ps with an increasing number of layers, while the reductive energy of A excitonic band decreases from 191.7 meV to 51.1 meV. The intriguing NLO response of MoS2 provides excellent potentials for the next-generation optoelectronic and photonic devices.
Ultrafast optics two-dimensional materials ultrafast photonic devices Photonic Sensors
2019, 9(1): 0101
Author Affiliations
Abstract
1 College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, China
2 No. 63880 Unit of P.L.A., Key Laboratory of Electro-Optical Countermeasures Test & Evaluation Technology, Luoyang 471003, China
3 Hu’nan Key Laboratory of Ultra-precision Machining Technology, Changsha 410073, China
4 College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, China
A model that considers both thermal expansion and thermo-optical effects is developed to investigate the transmission variation of optical coatings when they are exposed to an intense laser beam. Our results indicate that a higher gradient of the transmission spectrum curve at a certain wavelength leads to a more evident variation of the coating transmission. Three customized HfO2–SiO2 multilayer coatings with different transmission spectra are used to measure the transmitted power under the irradiation of a 1080 nm continuous-fiber laser. Excellent agreement is found between the experimental result and the theoretical prediction. Our result is helpful for the improvement of such devices in the application of high-power laser systems.
240.0310 Thin films 310.6188 Spectral properties Chinese Optics Letters
2015, 13(5): 052401
1 国防科学技术大学 光电科学与工程学院， 长沙 410073
2 中国人民解放军95844部队， 甘肃 酒泉 735018
针对MCT红外焦平面阵列器件普遍存在的光串扰问题进行研究，从器件内部结构上，建立了线阵器件理论计算模型，并基于载流子连续性方程，利用Comsol软件对光串扰的大小进行了数值定量计算，研究了不同探测器结构尺寸、温度和材料等参数对光串扰的影响; 从器件外部结构上，利用几何光学，研究了外部光学结构对光串扰的影响。研究结果表明，器件内部的衬底外延层厚度与器件外部的真空层对光串扰的影响最大，为今后红外焦平面器件结构的改进提供了一定的理论指导。
阵列探测器 Comsol软件 光串扰 HgCdTe HgCdTe linear array detector Comsol code optical crosstalk 强激光与粒子束
2012, 24(10): 2325
国防科学技术大学 光电科学与工程学院,湖南 长沙 410073
研究分析了CCD光电转换后信号电荷的传输过程以及激光高亮度的特点。认为高亮度的激光容易使感光二极管饱和,从而使光生电荷不通过读出脉冲控制而直接溢出至垂直CCD中,形成溢出信号电荷包;高亮度激光在垂直CCD内的漏光信号较强,从而直接在垂直CCD中形成漏光信号电荷包。溢出信号电荷包和漏光信号电荷包不依赖读出脉冲而出现于垂直CCD中,它们叠加在一起称之为次信号电荷包。次信号电荷包,经过垂直CCD的耦合转移动作,就形成了区别于激光主光斑的次光斑。研究中对次光斑的间距及循环移动的规律给出了定量的分析。次光斑的间距由CCD的转移频率和激光的重频频率所决定。而相邻帧中,主光斑与次光斑的间距有周期性的变化,从而造成了CCD输出视频中的次光斑循环移动。这种变化是由CCD垂直扫描周期被激光脉冲间隔时间整除后的余数所决定的。
高重频脉冲激光 主光斑 次光斑 面阵CCD high repetition pulses laser primary facula subordinate facula CCD
