Electroabsorption spectroscopy of trans-cis blend of highly ordered polyacetylene

Electroabsorption spectra have been measured for nonoriented trans-cis blend films of highly ordered ‘soluble’ polyacetylene in the spectral range 1.3 to 2.5 eV for different temperature and probe polarization. The electroabsorption spectra follow the second derivative of the absorption spectrum except the region below the absorption edge of the trans isomer. The observed electroabsorption for the cis isomer is considerably weaker than that for the trans isomer. The non-resonant nonlinear susceptibility χ(3)(ω; ω,0,0) of the ʹsoluble’ trans-(CH):x has been estimated to be ~2×10−11 esu.