【摘要】 实验观察到５２６ｕｍ基模高斯先来通过聚苯按／Ｎ－甲基－２－吮咯烷酮（ＮＭＰ）溶液时，在这场处产生了多个同心衍射圆环．该现象可以用高斯光束通过非线性介质时产生的空间自相位调制来解释．理论分析表明，对于薄样品，光束横截面上产生的非线性附加相移近似于高斯分布．通过测量衍射环个数，可以估算出聚苯胺／ＮＭＰ溶液(对５２６ｕｍ的吸收系数为０．５６ｃｍ^－１)的克尔常数γ≈４．４ｘ１０^－１０ｍ^２／Ｗ．更多还原

【Abstract】 Laser induced concentric diffraction rings are observed in the far field when the 526um TEM00 laser beam passes through the Polyaniline/N-Methyl-2-pyrrololidone (NMP) solution, which can be explained by the spatial self-phase modulation of the Gaussian beam passing through the nonlinear medium. The theoretical analysis indicates, to thin sample, the transverse nonlinear phase shift distribution is similar to a Gaussian function. According to the number of the diffraction rings, the Kerr constant of the Polyaniline/NMP solution (absorption coefficient 0. 56cm-1 at 526um) is evaluated to be 4. 4 x 10-10m2/W.更多还原