Polarization-dependent effects of refractive index change associated with photoisomerization investigated with Z-scan technique

The Z-scan technique is used to investigate the effects of refractive index change (RIC) associated with photoisomerization for two cases: in which the sample is pumped and probed by the same elliptically polarized light, and in which the sample is pumped by a linearly polarized light and probed by another linearly polarized light. Both experimental and theoretical results show that for the first case, this effect depends upon the polarization of the light; that is, when the polarization changes continuously from circularly polarization to linearly polarization, the effects of RIC becomes stronger. For the second case, the effect is similar to the effects of saturable Kerr effect, whose nonlinear coefficient n2 is measured.