Regularization method for solution of integral equation of laser intensity modulation method (LIMM) and its experimental verification

The laser intensity modulation method (LIMM) was developed for the determination of the spatial distribution of polarization through the thickness of a ferroelectric sample. One of the major drawbacks in the analysis of LIMM measurements is the necessity of solving a Fredholm integral equation of the first kind using experimental data. This is an ill-posed problem which can inherently yield a number of solutions, each of which satisfies the measured data to within experimental accuracy. A technique has been developed for solving this class of equations by a modification of the regularization method. The method has been verified by experimental measurements on multilayer samples composed of two or three sheets of polyvinylidene fluoride, poled in either a positive or a negative direction, or unpoled