Ultrafast optical Kerr effect of polybenzonitrile

Abstract.

 The subpicosecond time-resolved optical Kerr effect was used to determine the non-resonant optical nonlinearity of a new kind polynitrile: polybenzonitrile at a wavelength of 647 nm. A power-law dependence of the second-order hyperpolarizability γ₁₁₁₁ of the polybenzonitrile molecule on the average – polymerization – degree was discussed. From the transient response, which was primarily pulse limited, the relaxation time of the samples has been proved to be shorter than the laser pulse width.