A Comparison of Three Techniques for Solving the Fredholm Integral Equation of the Laser Intensity Modulation Method (LIMM)

• Published in: IEEE transactions on dielectrics and electrical insulation Vol. 16; no. 3; pp. 809 - 814
• Main Authors: Lang, S., Fleming, R.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Chemical lasers; Computer simulation; Electrical insulation; Electrodes; Fredholm integral equations; Frequency; Integral equations; Intensity modulation; Laser beams; Laser theory; Lasers; Modulation; Monte Carlo methods; Optical modulation; Polarization; Polymers; pyroelectricity; semiconductor lasers; Space charge; Spatial distribution; Transformations
• ISSN: 1070-9878; 1558-4135
• DOI: 10.1109/TDEI.2009.5128521

The Laser Intensity Modulation Method (LIMM) is widely used for the determination of the spatial distribution of polarization in polar ceramics and polymers, and space charge in non-polar polymers. The analysis of experimental data requires a solution of a Fredholm integral equation of the 1st kind. This is an ill-posed problem that has multiple and very different solutions. A number of methods have been used to solve this problem. In this paper, a comparison is made among three different techniques: the Scale Transformation Method, the Polynomial Regularization L-Curve Method and the Monte Carlo Method. The accuracy and ease of use of the three techniques are compared using both simulated and experimental data.