聚对苯撑乙烯衍生物/氯仿溶液的自衍射及光限幅特性的研究

用532 nm基模高斯光束对2-甲氧基5-丁氧基取代聚对苯撑乙烯的氯仿溶液进行激光诱导衍射实验及光限幅特性的研究.实验发现,当高斯光束通过样品溶液时,在远场处出现衍射环;随着入射功率的增大,衍射图案会发生显著的变化.理论分析表明,该现象可以用光克尔效应、热效应作用下的附加相位孔对入射光束的衍射行为来解释.还进一步研究了532 nm激光作用下样品溶液的光限幅特性,根据实验结果分析得出:由热效应引起的自衍射是产生光限幅特性的主要机制.

Study on Self-diffraction and Optical Limiting Property of Poly-Phenylene Vinylene Derivative/Chloroform Solution

By using the 532 nm TEM00 laser beam,the laser-induced diffractive and optical limiting properties of the(2-methoxy-5-butoxy)Poly-phenylene vinylene derivative/chloroform Solution are studied.When the 532 nm laser beam passes through the sample solution,the patterns of diffraction rings are observed in far field.With laser’s input power being increased,the patterns have apparent changes.These phenomena can be explained by the diffraction effect of the Gaussian beam from the laser-induced phase-hole in the nonlinear medium caused by Kerr effect and thermo-optic effect. Further, optical limiting properties of PPV derivative are discussed at 532 nm. According to experimental results, the main mechanism of optical limiting can be explained by the effect of diffraction rings caused by thermo-optic action.