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 χ⁽³⁾ of the C₆₀-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 χ⁽³⁾ of C₆₀ 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 χ⁽³⁾ measured by using different laser durations, and the third-order optical susceptibility χ⁽³⁾ of the fullerene-doped inorganic-organic hybrid materials measured by 30 fs pulse laser is a little smaller than that obtained by 200 fs pulse laser.