Tunable broadband polarization retarders

TL;DR

This paper introduces a tunable broadband polarization retarder made of stacked wave plates, which can be adjusted for specific retardance values while preserving wide spectral bandwidth, enhancing optical polarization control.

Contribution

It presents a novel composite retarder design that is tunable and broadband, using standard wave plates rotated at specific angles for customizable retardance.

Findings

Retardance can be tuned by adjusting the middle retarder.

The broadband spectral bandwidth is maintained during tuning.

The design is based on stacking standard wave plates at specific angles.

Abstract

We theoretically propose a type of tunable polarization retarder, which is composed of sequences of half-wave and quarter-wave polarization retarders, allowing operation at broad spectral bandwidth. The constituent retarders are composed of stacked standard half-wave retarders and quarter-wave retarders rotated at designated angles relative to their fast-polarization axes. The proposed composite retarder can be tuned to an arbitrary value of the retardance by varying the middle retarder alone, while maintaining its broadband spectral bandwidth intact.