A NONDESTRUCTIVE TECHNIQUE FOR THE DETERMINATION OF SPATIAL CHARGE AND POLARIZATION DISTRIBUTIONS IN INSULATING POLYMERS

Recently, a laser intensity modulation method (LIMM) has been developed to determine spatial distributions of both polarization and space charge in the bulk of polymeric insulators. Polarization arising from field-induced orientation of dipoles and trapped space charges provides pyroelectric current when a metal-polymer-metal sandwich is heated with a laser beam that is intensity modulated in an appropriate range of frequencies. Present work provides an improved analytical technique to transform the pyroelectric current-frequency data into a spatial distribution of polarization and space charges. Some experimental results with a polar polymer and the associated spatial distribution of polarization are presented in support of the mathematical model. © 1990 IOP Publishing Ltd.