1 山东大学晶体材料研究院，济南 250100
2 晶体材料国家重点实验室，济南 250100
3 中国工程物理研究院激光聚变研究中心，四川 绵阳 621000
高功率激光系统的发展对大尺寸、高性能磷酸二氘钾(DKDP)类晶体的需求越来越大。快速生长法较传统法可大幅缩短晶体生长周期，提高晶体生长效率。但是快速生长DKDP晶体锥面区和柱面区性能存在差异，导致不同位置的性能存在不均匀性，限制其在高功率激光系统中的应用。通过合成晶体生长溶液，采用点籽晶快速生长法生长了中等口径的高氘DKDP晶体，使用透过光谱，从线性吸收角度分析了快长DKDP晶体用作电光开关和频率转换器的可行性。结合Raman光谱技术及摇摆曲线的测试方法分析了晶体氘含量和结晶质量均匀性，为大尺寸DKDP的生长和应用提供参考。
点籽晶法 磷酸二氘钾晶体 氘含量 透过率 摇摆曲线 point seeding method potassium dideuterium phosphate crystals deuterium content transmittance rocking curve
1 北京科技大学 物理系, 北京 100083
2 山东大学 晶体材料国家重点实验室,济南 250100
3 潍坊医学院, 山东 潍坊 261053
大口径高能激光装置是各强国积极研究的重点项目。对装置内大口径光学元件损伤特性进行有效评估具有非常重要的意义，在此研究大尺寸光学元件表面损伤。通过分段拍摄、图像拼合、损伤点记录、统计与归纳等工作发现，不同尺寸损伤点的分布特性差异较大。结合统计学方法与类似实验对比、理论计算等方式对损伤点分布与样品辐照环境特性变化的关系进行分析。结果显示，损伤点的位置分布与辐照光束的能量密度关联紧密；系统光束(351 nm)在低于6 J/cm2时能量分布均匀，高于6.7 J/cm2时呈现较为明显的高斯分布状态。可以为大口径高能辐照环境的元件损伤特性评估提供有价值的参考，对大口径紫外激光器的日常运行与维护具有极其重要的工程意义。
DKDP 激光诱导损伤 损伤分布 大口径 高能激光 DKDP laser induced damage distribution large-aperture high-energy laser 强激光与粒子束
2021, 33(11): 111013
Author Affiliations
Abstract
1 State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
2 Key Laboratory of Functional Crystal Materials and Device, Shandong University, Ministry of Education, Jinan 250100, China
3 Chengdu Fine Optical Engineering Research Center, Chengdu 610041, China
Refractive indices for crystals ammonium dihydrogen phosphate (ADP), 30% deuterated ADP (DADP), 50% DADP, and 70% DADP are measured from 253 to 1529 nm with 5×10 6 accuracy. Numerical fits to modified double-pole Sellmeier equation are made. Second-harmonic generation, third-harmonic generation phase matching (PM) angles, and noncritical PM (NCPM) wavelengths are calculated using the Sellmeier parameters. The deuterated crystals show smaller PM angles than pure crystal. Fourth-harmonic generation process can be realized by DADP in smaller deuterium content than deuterated potassium dihydrogen phosphate (DKDP). The measured NCPM wavelengths are consistent with the calculated value. PM characteristics are compared between DADP and DKDP.
160.4760 Optical properties 160.4330 Nonlinear optical materials 260.1180 Crystal optics 190.4400 Nonlinear optics, materials Chinese Optics Letters
2015, 13(4): 041601
Author Affiliations
Abstract
1 Key Laboratory of Functional Crystal Materials and Device, Shandong University, Ministry of Education, Jinan 250100, China
2 Shanghai Institute of Optics and Fine Mechanics, CAS, Shanghai 201800, China
3 Chengdu Fine Optical Engineering Research Centre, Chengdu 610041, China
Three kinds of KH2PO4 raw material are used to grow deuterated potassium dihydrogen phosphate (DKDP) crystals by traditional and rapid growth methods, respectively. The growth habit dependence on the purity of raw material is described and analyzed. The optical properties including transmission spectra and laser-induced damage threshold of these crystals have been measured. It is found that the growth method affects the optical properties of crystal more obviously than the raw material with the mass content of main metal ions below 1 ppm. Moreover, the morphology of the core in the observed damage sites indicates that an explosion process probably occurs during laser-induced breakdown.
160.4330 Nonlinear optical materials 140.3330 Laser damage 300.6170 Spectra Chinese Optics Letters
2014, 12(10): 101604
1 山东大学 晶体材料国家重点实验室, 济南 250100
2 成都精密光学工程研究中心, 成都 610041
用点籽晶快速生长法在不同温度区间生长了四块氘含量60% DKDP晶体,观察了不同温度下晶体生长过程,同时测量了晶体的透过光谱、摇摆曲线和1053 nm激光损伤阈值。结果表明,在高温区间晶体生长外形优于低温生长的晶体。不同温区晶体的透过光谱并无明显变化,但是随着生长温度的降低,晶体的结构完整性变差,1053 nm激光损伤阈值降低。
DKDP晶体 温度 摇摆曲线 激光损伤阈值 DKDP crystal temperature rocking curve laser induced damage threshold 强激光与粒子束
2014, 26(1): 012006
Author Affiliations
Abstract
Potassium dideuterium phosphate (DKDP) with deuterium content of 60% and potassium dihydrogen phoshate (KDP) crystals are grown by "point-seed" rapid growth method. Optical property including transmittance spectra, conoscopic image, light scattering and laser damage threshold (LDT) are measured. The results show that although the infrared absorption edge of transmission spectra is obviously red-shifted, structure perfection and optical homogeneity of DKDP crystal became poorer. Light scattering have no obvious change. We also find that the value of LDT at 1 053 nm has a 2.5-3.8 \times increase compared with that tested at 526 nm and LDT of Z-cut samples is obviously higher than that of tripler-cut samples.
160.4330 Nonlinear optical materials 300.6170 Spectra 140.3330 Laser damage Chinese Optics Letters
2012, 10(s1): S11602
Author Affiliations
Abstract
1 State Key Laboratory, Crystal Materials of Shandong University, Jinan 250100, China
2 Department of Physics, Qilu Normal University, Jinan 250013, China
Ba impurity in potassium dihydrogen phosphate (KDP) is studied with the first-principle simulation method. The relaxed configurations and density of the states of KDP crystal with Ba impurity are calculated. We find that Ba can generate a K vacancy and an interstitial O-H unit for charge compensation. The band gap of KDP crystal narrowed down to about 3.9 eV, which is consistent with the experimental data from previously reported studies and indicates that Ba may be a source of low-damage threshold.
KDP晶体 钡 损伤 140.3330 Laser damage 140.3440 Laser-induced breakdown Chinese Optics Letters
2011, 9(9): 091402
1 山东大学 晶体材料国家重点实验室,济南 250100
2 中国工程物理研究院 上海激光等离子体研究所,上海201800
3 中国科学院 上海光学精密机械研究所,上海 201800
采用传统降温法,利用高纯原料从氘化程度为80%的溶液生长了四方相磷酸二氘钾(DKDP)晶体,并按Ⅱ类三倍频方式切割晶体。三倍频用DKDP晶体的最大问题在于其抗光伤阈值低于KDP晶体,严重限制了激光输出的能量密度和晶体使用寿命。考察了不同波长下三倍频DKDP晶体的损伤阈值,以及激光退火效应。实验表明,激光退火对于DKDP晶体的损伤阈值有显著的提升作用,基频、倍频、三倍频的提升效果分别达到1.4,1.9,2.7倍,是改善DKDP晶体抗光伤能力的有效途径。
四方相磷酸二氘钾晶体 三倍频 激光损伤 激光退火 DKDP crystal third harmonic generation laser-induced damage laser annealing
