Influence of structural surface roughness on self-excited oscillation of main amplification system of high power laser device
-
摘要: 对于采用离轴多程放大技术的高功率激光装置，抑制其自激振荡的技术具有重大研究价值。针对工程中发现的主放大系统小孔板附近结构表面比较光亮，当腔内放大器工作时，在增益足够条件下，光亮结构面和腔镜间形成谐振腔而产生自激振荡，烧蚀腔内器件的问题，基于蒙特卡洛方法模拟结构表面，依据几何光学原理推导了激光光束在结构表面反射模型，采用该模型代入工程中光路部分参数计算了主放大系统结构表面粗糙处理工艺和反射进入放大器内份额的关系，并将该表面处理工艺应用于工程中，通过增大结构表面粗糙度，使形成的谐振腔损耗大于增益，为抑制高功率激光装置主放大系统自激振荡提供了依据。Abstract: For high-power laser devices using off-axis multi-pass amplification technology, the technology to suppress self-oscillation is of great research value. It is found in engineering practice that the surface of the structure near the aperture of the main amplification system is relatively bright, thus when the amplifier is working, with sufficient gain, a resonant cavity is formed between the bright structural surface and the cavity mirror to generate self-oscillation and ablation. In this paper, this problem of the device is studied by using Monte Carlo method to simulate the surface of the structure. According to the principle of geometric optics, the reflection model of the laser beam on the surface of the structure is derived. The surface of the main amplification system is simulated using this model, and the parameters of the optical path are used to calculate the relationship between surface roughness and residual reflected light reflected into the amplifier. The surface treatment process is applied to our project. By increasing the surface roughness of the structure, the resonant cavity loss is greater than the gain, which provides a basis for suppressing the self-oscillation of the main amplification system of high-power laser devices.
-
图 1 放大器光路结构及腔镜背面自激振荡时间波形
Figure 1. Amplifier optical path structure and self-oscillation time waveform in the back of cavity mirror
图 2 空间滤波器小孔附近自激振荡烧蚀痕迹
Figure 2. Ablative trace near the aperture of the spatial filter
图 3 蒙特卡罗法构造的二维高斯粗糙面
Figure 3. Two-dimensional Gaussian rough surface constructed by Monte-Carlo method
图 4 模拟出的圆形光斑经高斯粗糙表面反射后的光斑
Figure 4. Simulated circular light spot which is reflected by a Gaussian rough surface
图 5 小孔板PA1与腔镜CM之间的谐振腔
Figure 5. Resonant cavity between the orifice plate and the cavity mirror
图 6 抛（喷）丸表面粗糙度比较样块
Figure 6. Surface roughness comparison of samples prepared by shot blasting
图 7 小孔尺寸、表面粗糙度与进入主放份额关系
Figure 7. Relationship between aperture size, surface roughness and the proportion of reflected laser entering the main amplification system
图 13 增大结构表面粗糙度前后的自激振荡波形测试
Figure 13. Self-oscillation waveform test before and after increasing the surface roughness of the structure
表 1 表面粗糙程度的定性划分
Table 1. Qualitative division of surface roughness
geometric statistics typical scattering characteristics representative surface subtle roughness δs＜0.1，l$\gg $λ specular reflection with specular reflection peak machine-finished surface, calm water surface slight roughness 0.1＜δs＜0.3，l$\gg $λ near diffuse reflection with peaks between mirror
and normal directionground surface, general machined surface strong roughness 0.3＜δs＜1，l≈λ diffuse reflection with backward enhancement and
significant depolarization effectartificial special surface extreme roughness δs＞1，l＜λ similar to an ideal reflector unknown surface 
下载: 导出CSV
表 2 比较样块表面工艺统计参数
Table 2. Comparison of sample surface process statistics
σ/μm l/μm δs 1# 0.51 4.23 0.171 2# 0.95 5.72 0.235 3# 1.46 7.24 0.285 4# 1.95 8.78 0.314
下载: 导出CSV
-
张小民, 魏晓峰. 中国新一代巨型高峰值功率激光装置发展回顾[J]. 中国激光, 2019, 46:0100003. (Zhang Xiaomin, Wei Xiaofeng. Review of new generation of huge-scale high peak power laser facility in china[J]. Chinese Journal of Lasers, 2019, 46: 0100003 甘啟俊, 姜本学, 张攀德, 等. 高平均功率固体激光器研究进展[J]. 激光与光电子学进展, 2017, 54(1):29-39. (Gan Qijun, Jiang Benxue, Zhang Pande, et al. Research progress of high average power solid-state lasers[J]. Laser & Optoelectronics Progress, 2017, 54(1): 29-39 谭吉春, 景峰, 朱启华, 等. 多通放大器腔内杂散光[J]. 强激光与粒子束, 2000, 12(2):159-163. (Tan Jichun, Jing Feng, Zhu Qihua, et al. Stray light inside multi-pass laser cavity of the SG-Ⅲ prototype module[J]. High Power Laser and Particle Beams, 2000, 12(2): 159-163 刘红婕, 朱启华, 蒋东镔, 等. 双程放大实验中自激振荡的抑制[J]. 强激光与粒子束, 2000, 12(s2):179-181. (Liu Hongjie, Zhu Qihua, Jiang Dongbin, et al. Restrain of the self-excitation oscillation in the two-pass amplification[J]. High Power Laser and Particle Beams, 2000, 12(s2): 179-181 Bowers M, Wisoff J, Herrmann M, et al. Status of NIF laser and high power laser research at LLNL[C]//Proc of SPIE. 2017: 1008403. Manes K R, Spaeth M L, Adams J J, et al. Damage mechanisms avoided or managed for NIF large optics[J]. Fusion Science & Technology, 2016, 69(1): 146-249. 李欣雪, 唐东成, 邓超兵, 等. 随机粗糙面研究参数特性分析[J]. 电子世界, 2017(10):55-55. (Li Xinxue, Tang Dongcheng, Deng Chaobing, et al. Analysis of parameter characteristics of random rough surfaces[J]. Electronics World, 2017(10): 55-55 doi: 10.3969/j.issn.1003-0522.2017.10.034 Zou M, Yu B, Feng Y, et al. A Monte Carlo method for simulating fractal surfaces[J]. Physica A Statistical Mechanics & Its Applications, 2007, 386(1): 176-186. Da B, Mao S F, Zhang G H, et al. Monte Carlo modeling of surface excitation in reflection electron energy loss spectroscopy spectrum for rough surfaces[J]. Journal of Applied Physics, 2012, 112: 034310. doi: 10.1063/1.4739491 田炜. 随机粗糙面光散射特性研究[D]. 陕西: 西安电子科技大学, 2009: 7-11.Tian Wei. Research on light scattering characteristics of random rough surfaces. Shanxi: Xidian University, 2009: 7-11 黄于恒. 粗糙面电磁散射数值方法研究[D]. 武汉: 华中科技大学, 2008: 7-9.Huang Yuheng, Research on numerical methods of electromagnetic scattering from rough surfaces. Wuhan: Huazhong University of Science and Technology, 2008: 7-9 Rui W, Guo L, Zhang Z. Scattering from contaminated rough sea surface by iterative physical optics model[J]. IEEE Geoscience & Remote Sensing Letters, 2017, 13(4): 500-504. Mohammed N A, Elkarim M A. Exploring the effect of diffuse reflection on indoor localization systems based on RSSI-VLC[J]. Optics Express, 2015, 23(16): 20297-20313. doi: 10.1364/OE.23.020297 Carbone N A, Baez G R, García H A, et al. Diffuse reflectance optical topography: location of inclusions in 3D and detectability limits[J]. Biomedical Optics Express, 2014, 5(5): 1336-1354. doi: 10.1364/BOE.5.001336 张晓晖, 张爽, 孙春生. 粗糙海面对高斯分布激光光束的反射模型推导[J]. 物理学报, 2016, 65:144204. (Zhang Xiaohui, Zhang Shuang, Sun Chunsheng. Modeling of Gaussian laser beam reflection from rough sea surface[J]. Acta Physica Sinica, 2016, 65: 144204 丁磊, 赵润昌, 梁樾, 等. 高功率激光装置预放大系统自激振荡抑制技术研究[J]. 激光与红外, 2007, 37(4):326-328. (Ding Lei, Zhao Runchang, Liang Yue, et al. Research of the technique of restraining the self-oscillations in the preamplifier system of high power laser facility[J]. Laser & Infrared, 2007, 37(4): 326-328 doi: 10.3969/j.issn.1001-5078.2007.04.009 -
点击查看大图
计量
- 文章访问数: 2341
- HTML全文浏览量: 574
- PDF下载量: 156
- 被引次数: 0
