Non-Hermitian curved space via inverted wave equation

TL;DR

This paper introduces a novel approach to designing non-Hermitian media with gain and loss for wave manipulation, surpassing traditional transformation optics and enabling reflectionless, nonreciprocal photonic devices.

Contribution

It presents a new method to create non-Hermitian curved-space media that allow advanced wave control beyond conventional transformation optics.

Findings

Designed non-Hermitian media with gain and loss for wave manipulation

Demonstrated wave control through amplitude, phase, and direction shunting

Achieved simple implementation in nonreciprocal photonic platforms

Abstract

Directly solving graded materials from amplitude and phase was a method developed following transformation optics (TO), which provided reflectionless media for an incidence wave. However, this inverting method gives Hermitian media thus not applicable to non-Hermitian (NH) photonics. In this Letter we then design NH media offering more freedom to manipulate waves of no reflection. Our picture of curved-space powered with gain and loss, is exemplified by three types: amplitude controlling, phase conversion, and direction shunting. These examples showcase precise wave manipulation in a surprisingly simple manner, which goes beyond convectional TOs and is implementable in nonreciprocal photonic platform.