Giant amplification of modes in parity-time symmetric waveguides

TL;DR

This paper demonstrates that parity-time symmetric waveguides can cause giant amplification of propagating modes, with small gain-loss gradients leading to significant beam magnification without distortion.

Contribution

It reveals how interference and gain-loss profiles in PT-symmetric waveguides lead to unprecedented amplification effects.

Findings

Beam magnification by several orders of magnitude

Amplification occurs without distortion of average amplitude

Small gain-loss gradients cause large amplification

Abstract

The combination of the interference with the amplification of modes in a waveguide with gain and losses can result in a giant amplification of the propagating beam, which propagates without distortion of its average amplitude. An increase of the gain-loss gradient by only a few times results in a magnification of the beam by a several orders of magnitude.