Author Affiliations
Abstract
1 Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai201800, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing100049, China
This paper investigates the monolithic edge-cladding process for the elliptical disk of N31-type Nd-doped phosphate laser glass, which will be utilized under liquid cooling conditions for high-power laser systems. The thermal stress, interface bubbles and residual reflectivity, which are due to high-temperature casting and bonding during the monolithic edge-cladding process, are simulated and determined. The applied mould is optimized to a rectangular cavity mould, and the casting temperature is optimized to 1000°C. The resulting lower bubble density makes the mean residual reflectivity as low as 6.75 × 10-5, which is enough to suppress the amplified spontaneous emission generated in the Nd-glass disk, and the resulting maximum optical retardation is converged to 10.2–13.3 nm/cm, which is a favourable base for fine annealing to achieve the stress specification of less than or equal to 5 nm/cm. After fine annealing at the optimized 520°C, the maximum optical retardation is as low as 4.8 nm/cm, and the minimum transmitted wavefront peak-to-valley value is 0.222 wavelength (632.8 nm). An N31 elliptical disk with the size of 194 mm × 102 mm × 40 mm can be successfully cladded by the optimized monolithic edge-cladding process, whose edge-cladded disk with the size of 200 mm × 108 mm × 40 mm can achieve laser gain one-third higher than that of an N21-type disk of the same size.
interface bubble monolithic edge-cladding process N31-type Nd-doped phosphate laser glass residual reflectivity stress birefringence High Power Laser Science and Engineering
2022, 10(2): 02000e14
1 中国科学院上海光学精密机械研究所强激光材料重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
硬包边是激光钕玻璃减少放大自发辐射和抑制寄生振荡的包边技术之一,残余应力是硬包边的一个重要参数。详细描述了激光钕玻璃硬包边过程中残余应力的来源,并利用有限元分析软件COMSOL Multiphysics,对硬包边浇注熔接过程中不同膨胀系数匹配条件和不同包边玻璃浇注温度下的残余应力分布进行了数值模拟。结果显示,激光钕玻璃和包边玻璃的膨胀系数差异愈小,产生的残余应力愈小;包边玻璃浇注温度愈高,则产生的残余应力愈大。硬包边实验结果表明:包边玻璃的膨胀系数和激光钕玻璃的膨胀系数愈相近,则残余应力就愈小,当包边温度在700~1200 ℃范围内时,残余应力随着包边温度的增加而增大。模拟结果与实验结果吻合,所以在硬包边的浇注熔接过程中,为了使残余应力最小,最佳策略是激光钕玻璃的膨胀系数和包边玻璃的膨胀系数尽量接近甚至相等,且包边温度尽量低。
材料 激光钕玻璃 硬包边 有限元分析 激光元件 应力双折射率 残余应力
Author Affiliations
Abstract
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
A novel four light ray path test method for measuring residual reflectance has been presented. Residual reflectance spatial distribution at a cladding interface was measured using the technique. Residual reflectance could be on the order of 10?5 by matching the refractive index of Nd:glass, polymer, and cladding glass and eliminating defects in the adhesive layer. Residual reflection spatial distribution appears to be similar to Newton rings due to the edge surface flatness. The relationship between the residual reflectance and the edge surface flatness was discussed, and the results revealed that the edge surface flatness is very important during the cladding process.
residual reflectance edge cladding Nd:glass amplifier Chinese Optics Letters
2020, 18(9): 091402
1 中国科学院上海光学精密机械研究所, 上海 201800
2 中国科学院大学, 北京 100049
为减少放大自发辐射和抑制寄生震荡，需在激光钕玻璃片侧面粘接一层吸收介质包边玻璃，其中，包边残余应力是粘接的一个重要参数。详细描述了激光钕玻璃与包边玻璃在包边粘接过程中粘接界面附近残余应力的来源，实验讨论分析了精密退火、加工、包边粘接等对界面附近残余应力的影响。结果表明，退火过程中的边缘应力对粘接界面附近残余应力影响比较大，且包边面加工面型匹配越差，则界面附近残余应力越大，而低收缩率和低模量的粘接胶对界面附近的残余应力影响较小。
激光技术 激光钕玻璃 包边 残余应力 应力双折射
1 中国科学院上海光学精密机械研究所, 上海 201800
2 中国科学院研究生院, 北京 100039
包边技术是提高大尺寸激光玻璃饱和增益系数的关键。为获得优质包边玻璃,以CuO和CuCl分别作为Cu2+的引入物质,采用传统的玻璃熔制方法,研究了Cu2+掺杂量和不同引入物质对P2O5-ZnO-Na2O体系玻璃形成区、析晶稳定性、物化性能以及吸收系数的影响。研究结果表明,CuO和CuCl都能增大P2O5-ZnO-Na2O体系的玻璃形成区、提高玻璃样品的析晶稳定性。玻璃样品的吸收系数随Cu2+掺杂浓度的增加而明显增大,当Cu2+掺杂摩尔分数达到6%时,样品在1053 nm处的吸收系数为59.46 cm-1,基本上达到了饱和状态。
材料 包边玻璃 磷酸盐玻璃 寄生振荡 吸收系数
