Polarimetry data, Images, Octave code, and other data from article: Imaging polarimeter with high-accuracy measuring principles in crystal optics

This data is a supplement to the article "Imaging polarimeter with high-accuracy measuring principles in crystal optics". The abstract is reproduced below.
The methods to produce this data are fully described in the associated manuscript. An imaging polarimeter based on the principles of high-accuracy polarimetry well known in crystal optics is proposed. The application of scientific digital cameras for performance light measurements leads to precise data on polarizers quality, i.e., maps of extinction ratio and transmission axis. Processing of numerous images, acquired at various settings in the polarizer-sample-analyser system, allows to determine the two-dimensional distribution of the phase retardation of birefringent plates. Several results of imaging polarimetry experiments on birefringent plates demonstrate the impact of multiple light reflections on the measured phase retardation values. Experimental data for LiNbO3 and SiO2 crystal plates have been presented, demonstrating the capabilities of the proposed type of imaging polarimeter in the crystal optics studies. This technique also allows the measurement of the eigen wave ellipticities, associated with the optical activity of crystals.