研究了2-(2′-羟基苯基)苯并噻唑(HBT)分子的激发态质子转移(ESPT)动力学过程及其其非线性光学特性。理论推导并求解了HBT分子在其双光子吸收区的双光子吸收系数、非线性折射率以及三阶非线性极化率;重点研究532 nm皮秒脉冲光激励下HBT分子双光子诱导ESPT过程对其非线性光学效应的影响,分析了四能态粒子分布,并建立了双光子诱导ESPT动力学模型,基于此模型确立了HBT分子烯醇式构型基态的双光子吸收截面。本文工作为进一步研究和开发此类材料的应用提供了一定的理论与实验依据。
Two-photon-induced excited state intra-molecular proton transfer(ESPT) process of 2-(2′-hydroxyphenyl) benzothiazole(HBT) in cyclohexane solution has been investigated using Z-scan technique with picosecond pulses at 532 nm wavelengh.The experiment and calculations suggested that HBT molecules have obvious two-photon absorption(TPA) under the 532 nm ps pulse laser irradiation.We focus on the calculation of TPA coefficient and nonlinear refraction index of HBT,and the theoretical computational results are in good agreement with the experimental ones.The numerical results have shown that HBT is a promising TPA materials and worthy of further study.This work provides theoretical and experimental basis for further research work and development of the application of such material.