A polarization gadget with two quarter wave plates: Application to Mueller Polarimetry

TL;DR

This paper demonstrates how two quarter wave plates can be used to transform polarization states and determine Mueller matrices, supported by geometric, analytical, and experimental methods.

Contribution

It introduces a novel approach to polarization transformation and Mueller matrix determination using only two quarter wave plates, combining geometric, analytical, and experimental techniques.

Findings

Multiple polarization transformations achievable with two QWPs.

Derived exact analytical expression for polarization state trajectories.

Experimental validation of Mueller matrix determination using QWPs.

Abstract

We show that there are number of ways to transform an arbitrary polarization state to another with just two quarter wave plates (QWP). We have verified this geometrically using the trajectories of the initial and final polarization states corresponding to all the fast axis orientations of a QWP on the Poincare sphere. The exact analytical expression for the locus of polarization states has also been given that describes the trajectory. An analytical treatment of the equations obtained through matrix operations corresponding to the transformation supports the geometrical representation. This knowledge can be used to obtain the Mueller matrix by just using quarter wave plates which has been shown experimentally by exploiting projections of the output states on the input states.