C_（60）薄膜双光子光学非线性与双光子跃迁

Two Photon Optical Nonlinearities and Two Photon Transitions in C60 Thin Film

我们用Ｚ－扫描方法测量了Ｃ６０薄膜在６３３ｎｍ处大的双光子吸收系数β≈５．４ｃｍ／Ｗ，并由此计算了Ｃ６Ｏ薄膜双光子共振三阶非线性极化系数的实部和虚部。与计算的Ｃ６Ｏ分子能级进行比较，讨论了它的共振双光子光学跃迁。

We present the two photon optical nonlinearities of C60 thin film at 633 nm.Large two photon absorption coefficient ￣ 5.4 cm/W was measured by Z-scan method,the real and the imaginary part of the resonant nonlinear susceptibility X(3) was calculated. From a comparison with the calculated energy levels of C60,the resonant two photon transitions were discussed.