Laser intensity modulation method: A technique for determination of spatial distributions of polarization and space charge in ferroelectric materials

A new method for measurino the spatial distribution of combined polarization and space charge in various ferroelectric materials has been developed. The technique, called the Laser Intensity Modulation Method (LIMM), is based upon measurement of the pyroelectric current generated by the material when it is heated with a laser beam which is intensity-modulated over a range of frequencies. A special analytical technique is used to transform the current-frequency measurements to spatial distributions. The method gives high resolution and is very stable with respect to measurement errors. The technique can be easily implemented in a laboratory with conventional equipment. The advantages and limitations of LIMM are illustrated by means of calculations based upon simulated data. Experimental results on polymers and ceramics are presented.