Nonlinear constant r | could be calculated according to the numbers of the diffraction rings . the sample ' s optical limiting properties were discussed . according to the experimental results , we estimated that the main mechanism of the optical limiting was from the thermo - optic effect 對2 -甲氧基5 -丁氧基取代ppv氯仿溶液進(jìn)行了激光誘導(dǎo)自衍射實驗,根據(jù)衍射環(huán)的個數(shù)估算出了樣品的非線性常數(shù);同時還對該樣品進(jìn)行了光限幅特性的研究,由實驗結(jié)果分析得出:由光熱效應(yīng)引起的自衍射是產(chǎn)生光限幅特性的主要機(jī)制。