摘要
在紫外光伴随下,用偏振态分别为s和p的HeNe激光器发出的632.8nm红光(均为10mW)交替激发螺恶嗪掺杂的聚甲基丙烯酸甲脂薄膜(SO/PMMA),用532nm的绿光(0.1mW)作为探测光记录光致双折射的动力学过程.实验发现透射信号被周期性调制,而且每次调制的最大值随时间逐渐减小并最终趋于稳定.指出了泵浦过程中的异构动态平衡与取向动态平衡并存的物理机制.
Photo-induced birefringence of spirooxazine-doped PMMA films is alternately pumped by s and p polarized He-Ne beams (632.8 nm) of 10 mW. A dynamics of photo-induced birefringence is recorded by a linearly polarized double-frequency Nd∶YAG laser (532 nm) of 0.1 mW as a probe beam. It is found that the transmittance signal is periodically modulated by the polarization of the pumping beams and the maximum of the transmittance signals in each period versus time drops gradually to a steady value. The equilibriums of photo-orientation and photo-isomerization induced by He-Ne laser are also investigated.
出处
《物理实验》
2005年第6期16-19,共4页
Physics Experimentation
关键词
螺恶嗪
部花青
光致双折射
泵浦光偏振态
spirooxazine
merocyanines
photo-induced birefringence
polarization of pumping beams
