摘要
用皮秒ＹＡＧ激光器的倍频光（５３２ｎｍ）和三倍频光（３５５ｎｍ），对偶氮苯材料作激发态增强的双波耦合实验研究，发现材料处于激发态受激发时的三阶非线性光学电极化率比电子均处于基态时增强一个数量级．激发态时的非线性时间过程也有所缩短．用激子相位空间充满理论，对实验结果进行了理论上的解释．
The 3rd nonlinear optical susceptibility χ (3) and its response time of the excited state of 4’ (2”,4”,6” trichlorophenazoamino) phenazo 4 nitrobenzene were measured with the double wave coupling technique of the YAG picosecond double (532nm) and triple (355nm) frequency laser. The measured χ (3) increases by one order of magnitude. Its response time is also of an improvement. The study shows that the excited state enhanced 3rd nonlinerar optical susceptibility is directly proportional to the population in the related excited state, and is saturated with the increase of the pumping laser. The theory of the phase space filling of excitons was used to explain the experiment results. The exciton length of 22×10 -8 cm in the sample was thus obtained from the theory fitted value, which agrees reasonably with the generally acceptable order of (20 50)×10 -8 cm.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
1999年第3期213-217,共5页
Journal of Infrared and Millimeter Waves
基金
国家自然科学基金
关键词
激发态增强
偶氮苯
三阶
非线性光学
excited state enhancement, azobenzene, third order nonlinearity, theory of phase space filling of excitons.
