Effect of illumination of organic dielectrics by radiation of an active medium

The effect of illumination of 16 organic dielectrics, including PMMA and polyethylene- and polyvinylchloride-based materials, on their electrical conductivity, permittivity, and tangent of the loss angle is examined. Light pulses of 20 ns duration, mainly with a wavelength of 510.6 nm, formed a large light spot which illuminates the entire sample for 3-5 s so that the light pulse power density at the sample surface reached 0.6-6.6 kW/cm 2 It has been found that illumination, as a rule, changes the electrical parameters of the dielectrics that relax with time to their initial or new equilibrium values. In the process of many-hour relaxation of some materials, their electrical conductivity reached a maximum. This is indicative of the fact that light radiation converts dielectrics into the electret state. ©2001 Plenum Publishing Corporation.