Li Xiang, Zhu Pengfei, Han Lihong, Zhang Tao, Jia Baonan, Li Shanjun, Chen Jun, Lei Ming, Lu Pengfei
State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing 100876, China.
School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China.
Heliyon. 2019 Mar 27;5(3):e01384. doi: 10.1016/j.heliyon.2019.e01384. eCollection 2019 Mar.
KDP crystal is showing a good property in high-power laser systems. However, working in a high-power environment is easy to have damaged-defect. Dehydration of KDP crystal is one of the damage phenomena. We explore the total energy and physical properties of the KDP crystal progressive dehydration by using First-principles calculations. It is found that the band gap of the KDP crystal gradually decreases with the deepening of dehydration, and there are many obvious defect states between 4 eV and 8 eV (the corresponding wavelength region is from 310 nm to 155 nm). It indicates that dehydration causes a reduction in the damage threshold of the KDP crystal. Our results indicate that these defect states are due to the change of hybridization type of P atoms, which is gradually transformed from original hybridization to hybridization in the dehydration process. An obvious redshift can be observed in the absorption spectrum, producing many distinct absorption peaks. All of the results can provide the good basis for deeply understanding the electronic and optical properties of the KDP crystal.
磷酸二氢钾（KDP）晶体在高功率激光系统中表现出良好的性能。然而，在高功率环境下工作容易出现损伤缺陷。KDP晶体脱水是损伤现象之一。我们通过第一性原理计算探索KDP晶体渐进脱水的总能量和物理性质。研究发现，随着脱水程度的加深，KDP晶体的带隙逐渐减小，在4电子伏特和8电子伏特之间（相应波长区域为310纳米至155纳米）出现许多明显的缺陷态。这表明脱水导致KDP晶体损伤阈值降低。我们的结果表明，这些缺陷态是由于P原子杂化类型的变化，在脱水过程中从原来的杂化逐渐转变为杂化。在吸收光谱中可以观察到明显的红移，产生许多明显的吸收峰。所有这些结果可为深入理解KDP晶体的电子和光学性质提供良好的基础。
