具有中心对称结构的3m点群晶体中紫外三次谐波的产生

研究了中心对称晶体中的三阶非线性频率转换,并在这类晶体中实现了紫外激光的有效输出.确定了负单轴晶体的相位匹配角公式及相应的相位匹配角.选择带有离域共轭π键的冰洲石晶体和α-BBO晶体进行实验.以飞秒激光作为基频光,在Ⅱ类相位匹配方式下,利用α-BBO晶体获得了最高单脉冲能量为37.6μJ的266nm紫外三次谐波,最高转换效率为2.5%;利用冰洲石晶体获得了最高单脉冲能量为19.3μJ的266nm紫外三次谐波,最高转换效率为1.25%.该研究验证了利用中心对称晶体的三阶非线性效应直接获得紫外激光的可行性和获得深紫外激光的可能性,为紫外非线性晶体的探索和深紫外激光的研究提供参考.     

飞秒激光诱导自组织纳米周期结构及其光学特性的研究进展

飞秒激光具有超快、超强的特点.飞秒激光微纳加工发展非常迅速. 本文综述了近十年来利用飞秒激光在金属、半导体、介质等各类材料中制备的纳米周期结构, 阐述了若干关于飞秒激光诱导纳米周期结构的物理机理的观点.讨论了基于偏振调制的多光束 干涉在半导体表面制备纳米周期结构,简要叙述了周期结构对材料光学特性的影响. 关键词： 飞秒激光 纳米周期结构 多光束干涉 光学特性     

Spectroscopic study of B2Σ+–X1 2Π1/2 transition of electron electric dipole moment candidate PbF

PbF, a valuable candidate for measuring the electron electric dipole moment (eEDM), is of great significance in measuring its spectrum and deriving its molecular constants in experiment. In the present work, the rovibronic spectrum of the B$^{2}{\Sigma }^{+}$-X$_{1}^{\, 2}{\Pi }_{1/2}$ transition of PbF in a wavelength range of 260 nm-285 nm is studied by the laser ablation/laser induced fluorescence method. The molecular parameters of the X$_{1}^{\, 2}{\Pi }_{1/2}$ (${v'}=0)$ and B$^{2}{\Sigma }^{+}$ (${v}'=0, 1$) states are derived from the recorded spectra of the (0, 0) and (1, 0) bands of the B$^{2}{\Sigma }^{+}$-X$_{1}^{\, 2}{\Pi }_{1/2}$ transition. Also, the Franck-Condon factors (FCFs) of the transitions between the B$^{2}{\Sigma }^{+}$ and X$_{1}^{\, 2}{\Pi }_{1/2}$ states are calculated by the RKR/LEVEL method and the Morse potential method, respectively.     

微波辐射促进的3-烷基取代咪唑并[1,5-a]吡啶合成

分别在常规加热和微波辐射条件下, 由双(2-吡啶甲酰)、二(2-吡啶)甲酮与脂肪醛及醋酸铵在醋酸溶剂中反应成功地制备了3-烷基取代的咪唑并[1,5-a]吡啶. 实验结果表明: 微波法比传统的合成方法产率高、反应时间短. 产物的结构经过¹H NMR, MS和元素分析表征.