Chiral polarizer based on encircling EP

TL;DR

This paper introduces a novel on-chip chiral polarizer based on encircling an exceptional point in an anti-PT symmetric system, enabling asymmetric polarization control with potential applications in telecommunication signal encoding.

Contribution

The work demonstrates, for the first time, chiral polarization switching using an anti-PT symmetric system encircling an EP, with practical on-chip implementation and polarization encoding applications.

Findings

Achieved over 10 dB polarization extinction ratio in both directions.

Demonstrated potential for polarization encoding in telecommunication signals.

First on-chip realization of chiral polarization manipulation based on encircling an EP.

Abstract

Encircling an exceptional point (EP) in a parity-time (PT) symmetric system has shown great potential for chiral optical devices, such as chiral mode switching for symmetric and anti-symmetric modes. However, the chiral switching for polarization states has never been reported although chiral polarization manipulation has significant applications in imaging, sensing, and communication etc. Here inspired by the anti-PT symmetry, we demonstrate an on-chip chiral polarizer by constructing polarization-coupled anti-PT symmetric system for the first time. The transmission axes of the chiral polarizer are different for forward and backward propagation. A polarization extinction ratio of over 10 dB is achieved for both propagating directions. Moreover, a telecommunication experiment is performed to demonstrate the potential applications in polarization encoding signals. It provides a novel functionality for encircling-an-EP parametric evolution and offer a new approach for on-chip chiral polarization manipulation.