Two-and three-dimensional analysis of polarization profiles in electret materials with thermal pulses

Three-dimensional polarization distributions in thin electret films can be measured non-destructively using the thermal-pulse technique and the Laser Intensity Modulation Method (LIMM). However, the task of calculating the polarization distribution from the experimentally measured electric current is an ill-posed problem and requires special deconvolution techniques. While the analysis of one-dimensional sample geometries is well understood, there has been no such solution for the two- and the three-dimensional cases. In the past, thermal-pulse experiments have therefore been analyzed using the established one-dimensional techniques, thus sacrificing lateral resolution. In this work, the current signal from several neighboring spots along a scan line is coupled together, and a Monte Carlo method is used for the deconvolution. Preliminary results show that lateral polarization discontinuities are more accurately reproduced with the new approach, resulting in a higher lateral resolution.