足球烯分子三阶非线性光学性质的研究

Third-order nonlinear optical properties of fullerene molecules

报道了有关足球烯分子甲苯溶液中简并四波混频实验.测量出足球烯C_(70)分子和C_(60)分子的三阶超极化率张量y_(1111)分量分别为1.2×10^(-30)esu和4.0×10^(-31)esu.对应于固体样品的三阶非线性光学系数X_(1111)分量分别是2.5×10^(-8)esu和8.5×10^(-9)esu.此结果表明了足球烯分子是现有的非线性光学材料中具有较大三阶非共振电子极化率材料之一.文中还利用自由电子模型解释了非线性光学极化率的起源.

The third- order nonlinear optical properties of two kinds of fullerenes (molecules of C60 and C70), which are solved in toluene, were studied through a degenerate four wave mixing process respectively. The third-order hyperpolarizabilities γ1111 of C70 molecule and C60 molecule are measured to be 1. 2 × 10-30esu and 4. 0 × 10-31esu, corresponding to an estimated third-order optical susceptibility x1111(3) of 2. 5 × 10-8esu and 8. 5× 10-9esu for solid-state materials, respectively. The origin of the large nonlinear optical response of fullerene family is explained successfully with the free electron model.