纳秒激光对磷酸二氢钾晶体的辐照效应及其损伤机理研究  

Irradiation Effects of Nanosecond Laser on Potassium Dihydrogen Phosphate Crystals and Its Damage Mechanisms

作　　者：郜洋 陈元攀 周鑫[1] 王玉冉 马婷婷[1] 张丽卿 周磊[1] 郝辰春 邱荣[1] GAO Yang;CHEN Yuanpan;ZHOU Xin;WANG Yuran;MA Tingting;ZHANG Liqing;ZHOU Lei;HAO Chenchun;QIU Rong(Joint Laboratory of Extreme Conditions,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Xinjiang University of Science and Technology,Korla 841000,Xinjiang,China)

机构地区：[1]西南科技大学极端条件物质特性联合实验室,四川绵阳621010 [2]新疆科技学院,新疆库尔勒841000

出　　处：《原子核物理评论》2024年第4期1050-1057,共8页Nuclear Physics Review

基　　金：国家自然科学基金项目(11675231);四川省重点研发项目(2022YFG0263);西南科技大学引进人才项目(21zx7109,21zx7110)。

摘　　要：借助场发射扫描电子显微镜(FE-SEM)和红外光谱(IR)微区分析技术,研究KDP晶体被不同波长的纳秒激光、以不同能量密度辐照后的表面形貌、微结构、化学键振动以及晶体光学性能随激光能量密度的变化规律。SEM结果表明,随着激光辐照能量密度的增加,KDP晶体表面损伤呈现三个明显区域,损伤面积随激光能量密度的增加非线性地增大;同时,相同能量密度下,355 nm激光形成的损伤面积远大于1064 nm激光的损伤面积。红外光谱分析表明,辐照导致KDP晶体氢键断裂、脱水,PO_(4)^(3-)四面体和H_(2)PO_(4)^(-)基团中的化学键振动混乱,并且有P=O和P-H键生成。同时发现,辐照后的KDP晶体表面反射率下降,被潮解。而且,随激光能量密度的增加,KDP晶体在激光能量沉积热效应的作用下,中心区域先损伤,再退火修复,之后再次损伤;其中,KDP晶体被激光以10 J/cm^(2)的能量密度辐照后,中心区域所有化学键振动明显减弱,甚至消失,损伤最重。The surface morphology,microstructures,chemical bond vibrations and optical performances of Potassium dihydrogen phosphate(KDP)crystals induced by nanosecond laser with different wavelengths,are studied by means of field emission scanning electron microscopy(FE-SEM)and infrared spectroscopy(IR)microanalysis techniques at different energy densities.SEM results showed that with the increase of laser irradiation energy density,the damage region on KDP surfaces presented three parts evidently.And the damage area increases nonlinearly with the laser energy density.Meanwhile,at the same energy density,the damage area induced by the 355 nm nanosecond laser is much larger than that of the 1064 nm nanosecond laser.Infrared spectroscopy results revealed that the laser irradiation leads to a break in hydrogen bonds and a dehydration of KDP crystals,in conjunction with a generation of P=O and P-H bonds due to the vibrational mode disorder of the PO_(4)^(3-)tetrahedron and H_(2)PO_(4)^(-)groups after laser irradiation.Simultaneously,after irradiation,the surface reflectivity of KDP crystals decreased and the surface is roughened and deliquesced.Moreover,with the increase of the laser energy density,the central region of the KDP crystal is damaged firstly,and then is annealed and repaired,finally is destroyed again under the thermal effects of the laser energy deposition.In addition,after irradiation with the energy density of 10 J/cm^(2),all vibration modes of central regions of KDP crystals weaken or even disappear,and the sever damage occurs.

关 键 词：纳秒激光辐照 KDP晶体 光学性能 微结构 化学键振动 

分 类 号：O469[理学—凝聚态物理]