New non-destructive method of diagnostics and characterization of ACTFEL devices based on analysis of experimental and calculated photodepolarization spectra is proposed. This method gives an important information concerning the signa nd spatial distribution of polarization charge which influence significantly on characteristics of ACTFEL devices. The methodology and various variants of the method are considered. The simulation of PDP spectra is provided. Capabilities of the method are illustrated by the PDP spectra of ZnS:Mn and SrS:Ce devices fabricated by various techniques.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.