Third-order nonlinear optical properties of GeS(2)-Sb(2)S(3)-CdS chalcogenide glasses

The third-order nonlinear optical properties of GeS(2)-Sb(2)S(3)-CdS chalcogenide glasses were investigated utilizing the Z-scan and femtosecond time-resolved optical Kerr effect (OKE) methods at the wavelength of 800 nm, respectively. The compositional dependences were analyzed and the influencing factors including the linear refractive index, the concentration of lone electron pairs, the optical bandgap and the amount of weak covalent/ homopolar bonds were discussed. A glass, i.e. 76GeS(2)·19Sb(2)S()·5CdS, with large nonlinear refrative index (n(2) = 5.63 × 10(-14) cm(2)/W), low nonlinear absorption coefficient (β = 0.88 cm/GW) and minimum figure of merit (FOM = 2βλ/n(2) = 2.51) was finally prepared. The electronic contribution in weak heterpolar covalent and homopolar bonds are responsible for large n(2) in chalcogenide glass, and the Sheik-Bahae rule combining the Moss rule are proved to be an effective guidance for estimating the third-order nonlinearities and further optimizing the compositions in chalcogenide glasses.