# Polarimeters for the Detection of Anisotropy from Reflectance

## TL;DR

The paper explores how polarimeters can detect surface anisotropies by analyzing reflected laser light's polarization state.

## Contribution

The study introduces polarimetry as a complementary method to ellipsometry and camera imaging for analyzing surface anisotropies.

## Key findings

- Polarimetry can detect birefringence and dichroism in materials with linear patterns.
- Back-reflected light polarimetry complements ellipsometry and four-polarisation camera imaging.
- Experiments were conducted using a microscope to validate the method.

## Abstract

Polarimetry is used to determine the Stokes parameters of a laser beam. Once all four S0,1,2,3 parameters are determined, the state of polarisation is established. Upon reflection of a laser beam with the defined S polarisation state, the directly measured S parameters can be used to determine the optical properties of the surface, which modify the S-state upon reflection. Here, we use polarimetry for the determination of surface anisotropies related to the birefringence and dichroism of different materials, which have a common feature of linear patterns with different alignments and scales. It is shown that polarimetry in the back-reflected light is complementary to ellipsometry and four-polarisation camera imaging; experiments were carried out using a microscope.