Real-time polarization tuning in Mach-Zehnder interferometer using electro-optically modulated twist angles of nematic liquid crystal Note: This paper has been accepted for publication in "Journal of Theoretical and Applied Physics"

TL;DR

This paper presents a theoretical method for real-time, voltage-controlled polarization tuning in a Mach-Zehnder interferometer using a twisted nematic liquid crystal, enabling dynamic polarization manipulation.

Contribution

It introduces a novel electro-optic framework for actively controlling polarization states in interferometers with potential advantages over static methods.

Findings

Voltage-dependent polarization rotation enables tunable control of the output polarization.

The system maintains full coherence with a degree of polarization equal to 1.

Manipulation of linear polarization orientation is achieved through voltage adjustments.

Abstract

We propose a theoretical framework to dynamically control the degree of polarization of light by using the superposition of incoherent orthogonally polarized beams in a Mach-Zehnder interferometer incorporating a twisted nematic liquid crystal cell in one of its arms. The liquid crystal acts as an elecro-optically controlled polarization rotator, where the applied electric field changes the twist of molecules inside the nematic liquid crystal, thereby altering the plane of polarization. This controllable voltage dependent polarization rotation causes manipulation of the output degree of polarization. The resulting system allows real-time, tunable control over the degree of polarization, offering advantages over traditional static or reflection-based approaches, which often suffer from intensity losses or manual errors. We also observe that in the interference of fully coherent orthogonally polarized beams through a similar configuration, the degree of polarization is always equal to 1, whereas the orientation of linear state of polarization is changed with voltage.