Laser Metrology of Anisotropic Polymer Layers Structure of Materials for Packaging Industry

Abstract

We have proposed the use of a laser-polarimetric method, as more informative in terms of displaying optically inhomogeneous structures by using spatially coherent filtering. The filtering method consists in the fact that the spatial-frequency structure of the Fourier images of laser polarization images of the polycrystalline component of the polymer ball is different for its large-scale (with predominant linear birefringence) and small-scale (deep-like with predominant circular birefringence) components. By using spatial-frequency filtering, it was possible to isolate either low-frequency or high-frequency components, which, by means of the inverse Fourier transform, can be converted into the corresponding ‘filtered’ images of different-scale birefringent structures of various nature. The results of the development of a new method of Fourier-Stokes polarimetry of spatial-frequency spectra of laser polarization images of various model objects are also presented, which is based on the use of statistical analysis of polarization maps with the determination of statistical moments of 1–4 orders. The results obtained made it possible to identify the following diagnostically sensitive parameters to changes in birefringence (anisotropy). Differences in the statistical moments of the 3rd and 4th orders, which characterize the distribution of the large-scale component of the polarization azimuth map, for both types of networks, range from 2 to 3.5 times. Statistical moments of the 2nd–4th orders of polarization distributions of maps of the small-scale component of optically anisotropic cylinders range from 1.5 to 4 times.

Keywords

• applied programming
• polymers
• publishing
• digital and graphic information
• packaging materials
• materials science