摘要
两束强度相等的相干光小角度在乙基橙-聚乙烯醇(EO/PVA)膜中耦合时,产生自衍射现象。对自衍射效率的动态特性进行了实验研究,实验表明:1)当入射光强较小(I为100 mW/cm^2)时,一阶衍射效率η随照射时间的延长从零上升至一稳定值;2)入射光强较大(I为480 mW/cm^2)时,一阶衍射效率η从零开始迅速上升到一最大值ηm后再降至一稳定值ηs。以耦合光在膜中的干涉光场对trans-cis态的分子数分布进行调制而形成的粒子数光栅为模型,对衍射效率的动态特性进行了理论分析,理论与实验结果相符合。
When two coherent beams illuminate into the ethyl orange doped polymer film with small angle and equal intensity,the phenomena of self-diffraction occur.The dynamic characteristics of self-diffraction efficiency were explored experimentally.The results are the following：1） The diffraction efficiencyηincreases monotonously from zero to a stable valueη_s with the illumination time illuminated by lower intensity（I is 100 mW/cm^2）.2） The diffraction efficiencyηincreases to a maximumη_m at first and then decreases to a stable valueη_s illuminated by higher intensity.The phenomenon is analyzed theoretically by the model of population grating,which is formed by the molecules populations of trans and cis modulated by the coherence optical field.The theoretical results are consistent with the experimental results.
出处
《量子电子学报》
CAS
CSCD
北大核心
2011年第2期178-182,共5页
Chinese Journal of Quantum Electronics
关键词
非线性光学
自衍射
粒子数光栅
乙基橙
nonlinear optics
self-diffraction
model of population grating
ethyl orange
