Rk. Meyer et al., RE-CHI((3)), RE-CHI((5)), AND RE-CHI((7)) MEASURED IN POLY(PHENYLENE ETHYNYL SILANE)S BY THE Z SCAN TECHNIQUE, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 256, 1994, pp. 597-604
Optical nonlinear susceptibilities were measured in Poly(phenylene eth
ynyl silane) (PPES1) and Poly(phenylene ethynyl disilane) (PPES2) at 5
90nm and 1064nm. Both the real and imaginary parts of chi((3)) were ev
aluated with the Z scan technique using closed and open apertures, res
pectively. Closed aperture scans of PPES1 exhibited the classic negati
ve Re chi((3)) peak valley signature, whereas, closed aperture scans o
f PPES2 displayed interesting additional features. These features are
present at both 590nm and 1064nm, and indicate the presence of alterna
ting sign higher order nonlinearities with negative chi((3)), positive
chi((5)), and negative chi((7)).