Third-order nonlinear optical properties of the Na2S-PbS-GeS2 sulfide glasses and the Na2S-PbO-GeS2 oxysulfide glasses

The third-order optical nonlinearity of glasses of the Na2S-PbS-GeS2 and Na 2S-PbO-GeS2 systems was measured by third harmonic generation method. The t hird-order nonlinearities of glasses of both systems increase with the incr easing lead content. The maximum value of the third-order optical nonlinear ity was 3.00 x 10(-12) esu. The addition of PbO basically has little influe nce on third-order optical nonlinearity, and the largest nonlinearity is 1. 49 x 10(-12) esu. The minimum appearing at 15 mol % PbO can be explained by the decrease of number density of lead and sulfur. Chemical durability of oxysulfide glasses is superior to that of a pure sulfide system; thus the a ddition of PbO is important in this sense.