Study of a bi-axial (KTP) crystal using Double Stokes Mueller Polarimetry

TL;DR

This paper demonstrates the use of Double Stokes Mueller Polarimetry to characterize a large KTP crystal, extracting detailed optical and structural properties that are difficult to measure with traditional methods.

Contribution

The study validates DSMP as an effective technique for characterizing large KTP crystals, providing insights into their susceptibility tensor components and axes orientation.

Findings

Successfully extracted the crystal's double Mueller matrix

Determined the crystal axes orientation using DSMP

Compared DSMP results with X-ray and Laue diffraction

Abstract

We report the significance of the double Stokes Mueller polarimetry (DSMP) technique, to characterize a large size (3 X 3 X 5mm) KTP (Potassium titanyl phosphate) crystal. The crystal undergoes second harmonic generation with type II phase matching. The study of standard KTP crystal using the DSMP technique helps to validate the efficiency of this technique. We were able to extract the crystal's double Mueller matrix, the relative contribution of the susceptibility tensor components, the phase difference between the susceptibility tensor components, etc. We could determine the crystal axes orientation using this optical technique, which was not possible through a single crystal X-Ray diffraction technique for such a large size crystal for which both optic axes and crystallographic axes are the same. Axes direction determined from polarization microscope measurements and Laue diffraction measurements on KTP crystal is compared with those obtained from DSMP measurements.