二芳基乙烯光致各向异性动态特性研究

Dynamic properties of photoinduced anisotropy of diarylethene

建立了光致变色二芳基乙烯样品光致各向异性动力学的理论模型.计算了在线偏振光激发下,二芳基乙烯分子数密度、光致二向色性和光致双折射随时间(曝光量)的动态变化曲线.结果表明,随着激发曝光量的增加,二芳基乙烯呈色态分子数密度不断下降直至饱和,光致各向异性随曝光量增加先增加,达到最大之后开始下降,最佳曝光量为260 J/cm2.利用正交偏振检测方法测量了反映材料各向异性的探测光透过率动力学曲线,并与理论计算结果进行了比较,二者基本相符.

A theoretical model has been put forward to describe the dynamic properties of photoinduced anisotropy in photochromic diarylethene/PMMA film. The kinetic curves of molecule concentration, photoinduced dichroism and birefringence are calculated under the condition of excitation by linearly polarized light. The results show that the color molecule concentration decreases with the increase of the excitation exposure until the saturation point is reached. The photoinduced anisotropy increases to a maximum and then decreases with the exposure increasing. The optimal exposure is 260 J/cm^2 . Using the orthogonal polarization detection, the transmittance of probe beam reflecting the anisotropy is measured. The experimental result and the theoretical calculation are essentially consistent.