富勒烯有机-无机杂化材料的非共珍三阶非线性光学特性

采用中心波长800 nm、脉宽30 fs的超短激光脉冲,通过飞秒光开关技术(Optical Kerr Shutter,OKS)对富勒烯有机-无机杂化材料的飞秒超快非线性特性进行了实验研究.获得270 fs的开关时间,所得的富勒烯有机-无机杂化材料的三阶非线性系数X~(3)约为4.5×10~(-4) esu,比C_(60)分子的三阶非线性系数X~(3)高一个数量级.通过实验测定的光克尔信号强度与激发光和探测光偏振方向夹角的依赖关系表明:30 fs的超短激光脉冲激发富勒烯有机-无机杂化材料的克尔信号主要是源于光诱导双折射效应,而非用200 fs的超短激光脉冲时来自瞬态栅的自衍射效应.

Off-resonant Third-order Nonlinear Optical Properties of Fullerene-doped Inorganic-organic Hybrid Materials

The ultrafast nonlinear optical properties of the fullerene-doped inorganic-organic hybrid materials are investigated by the femtosecond optical Kerr shutter (OKS) technique at wavelength of 800 nm. The OKS in the sample symmetrical with the full width at half maximum (FWHM) of 270 fs is gained. The non-resonant third-order optical susceptibility X~(3) of the C_(60)-doped inorganic-organic hybrid materials is measured to be about 4.5 × 10~(-14) esu, which is one order magnitude more than the values of X~(3) of C_(60) molecule. Measurements for the dependence of Kerr signals on the polarization angle between are pump and probe beams show that the Kerr signals induced by 30 fs pulse laser arose are mainly from the photoinduced birefringence effect and not from a laser-induced transient grating as observed when using a 200 fs pulse laser. So there is a little difference between the values of the third-order optical susceptibility X~(3) measured by using different laser durations, and the third-order optical susceptibility X~(3) of the fullerenedoped inorganic-organic hybrid materials measured by 30 fs pulse laser is a little smaller than that obtained by 200 fs pulse laser.