Activation volume associated with the relaxation of the second order nonlinear optical susceptibility in a guest-host polymer

The volume associated with the relaxation of the second order nonlinear optical susceptibility in a guest-host polymer was determined by measuring the change in the rate of decay of the second harmonic signal from poled films as a function of hydrostatic pressure. The logarithm of the decay rates determined from Kohlrausch–Williams–Watt fits was found to vary linearly with pressure from 1–2100 atm. Above 2100 atm a saturation effect was observed. An activation volume of 86±2 cm3/mole, nearly equal to the size of one monomer unit, was found.