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
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
中国科学院上海光学精密机械研究所激光玻璃研发中心, 上海 201800
报道了磷酸盐激光钕玻璃的连续熔炼线，以及采用连续熔炼工艺获得的400 mm 口径N31 钕玻璃的主要性能。连熔所制备的N31-35 钕玻璃的掺杂离子浓度为3.47(±0.02)×1020 cm-3；1053 nm 处的折射率为1.5336±0.0005；400 nm 处的吸收系数平均值为0.098 cm-1；1053 nm 处的激光波长损耗为0.13~0.15% cm-1；3000 cm-1 处的吸收系数平均值为0.83 cm-1。400 mm 口径连熔N31 钕玻璃的透射波前畸变在633 nm 处小于λ/3 波长。采用1053 nm、脉冲为3 ns激光作用下连熔钕玻璃的体破坏阈值大于40 J/cm2。结果表明，在N31 钕玻璃的连续熔炼工艺中，除铂金和除水都取得了很好的效果。
光学制造 激光钕玻璃 连续熔炼工艺 损耗 增益系数
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
Author Affiliations
Abstract
The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses (x=0 to 7 mol%) are investigated. Both Raman and IR spectra reveal that discrete phosphate species ([PO4]^{-3}, [PO3O_{1/2}]^{-2}) with low polymerization degree can be formed in the silicate glass. These phosphate structures scavenge non-bridging oxygen ions and cations from the silicate network, resulting in an increase of the glass transition temperature. According to the Judd-Ofelt intensity parameters (\Omega2;\Omega4;\Omega6) of Er3+, the asymmetry of local environment around Er3+ becomes higher, and the bond covalency between Er3+ and O^{2-} decreases after P2O5 is introduced. In the emission spectra, photoluminescence intensity increases with increasing P2O5 concentration and the spectra are inhomogeneously broadened, revealing that the ligand electric field around Er3+ is dramatically changed, and the glass matrix becomes disordered.
160.2750 Glass and other amorphous materials Chinese Optics Letters
2012, 10(7): 071602
Author Affiliations
Abstract
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 2018002 Physical Chemistry of Luminescent Materials, University of Lyon, UMR CNRS 5620, Villeurbanne 69622, France
Yb-Er codoped Na2O-Al2O3-P2O5-xSiO2 glasses containing 0-20 mol% SiO2 were prepared successfully. The addition of SiO2 to the phosphate glass not only lengthens the bond between P^{5+} and non-bridging oxygen but also reduces the number of P=O bond. In contrast with silicate glass in which there is only four-fold coordinated Si^{4+}, most probably there coexist [SiO4 tetrahedron and [SiO6] octahedron in our glasses. Within the range of 0-20 mol% SiO2 addition, the stimulated emission cross-section of Er^{3+} ion only decreases no more than 10%. The Judd-Ofelt intensity parameters of Er^{3+}, \Omega_{2} does not change greatly, but \Omega_{4} and \Omega_{6} decrease obviously with increasing SiO2 addition, because the bond between Er^{3+} and O^{2-} is more strongly covalently bonded.
镱铒共掺磷酸盐玻璃 氧化硅 拉曼光谱 Judd-Ofelt参数 160.2750 Glass and other amorphous materials 160.5690 Rare-earth-doped materials 300.6450 Spectroscopy, Raman 300.6170 Spectra Chinese Optics Letters
2009, 7(1): 0156
