Third- and second-order optical nonlinearity of Ge-Ga-S-PbI2 chalcohalide glasses

Two series of metal iodide doped chalcolialide glasses (100-2x)GeS2 (.) xGa(2)S(3) (.) xPbI(2) (0 <= x <= 20) and (100-x)(0.8GeS(2) (.) 0.2Ga(2)S(3)) (.) xPbI(2) (0 <= x <= 15) were prepared and characterized. The microstructure of these glasses has been studied by Raman scattering spectra. Utilizing fermosecond time-resolved optical Kerr effect (OKE) technique at the wavelength of 820 nm, a largest third-order nonlinearity chi((3)) of 2.07 x 10(-13) esu was obtained for the 90GcS(2) (.) 5Ga(2)S(3) (.) 5PbI(2) glass, and it decreases with the addition of PbI2 in both two series. After thermally poled, second-harmonic generation (SHG) has been observed in these glasses according to Maker fringe method and a large second-order nonlinearity chi((2)) as well as 4 pm/V was obtained for the 70GeS(2) (.) 15Ga(2)S(3) (.) 15PbI(2) glass. The variations of chi((2)) and chi((3)) on glass composition are ascribed to the evolution of micro-structural units in glass. These novel chalcohalide glasses would be expected to be the promising candidate materials for nonlinear optical devices. (c) 2006 Elsevier Inc. All rights reserved.