Stability of active photonic metasurface pairs

Constantinos Valagiannopoulos,Sergei A Tretyakov

doi:10.1088/1367-2630/ac37ac

Constantinos Valagiannopoulos, Sergei A Tretyakov

Open Access

https://doi.org/10.1088/1367-2630/ac37ac

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Abstract

Adding active components to a photonic device may dramatically enrich and improve its performance but, at the same time, creates the risk of instability, namely, occurrence of unwanted self-oscillations. Stability considerations are not always given the attention they deserve when setups employing gain media are investigated; thus, the desired effects or reported regimes may not be achievable. In this work, a generic electromagnetic configuration comprising a pair of planar impedance metasurfaces is examined and analytical stability conditions for its operation are derived. The obtained results for the analyzed basic module can shed light on the stability conditions of more complex active systems that incorporate such components and serve a broad range of applications from imaging and polarization engineering to invisibility cloaking and wavefront transformations.

Highlights

Active media, namely substances that are able to pump extra energy into a device, have revolutionized numerous photonic setups by giving them unique utilities via loss compensation, dynamically controlled tunability, and configurability [1]
A generic electromagnetic configuration comprising a pair of planar impedance metasurfaces is examined and analytical stability conditions for its operation are derived
The objective of this paper is to systematically examine the stability conditions of a basic ubiquitous photonic setup defined by two coupled planar metasurfaces, which has not been yet scrutinized

Summary

Introduction

Namely substances that are able to pump extra energy into a device, have revolutionized numerous photonic setups by giving them unique utilities via loss compensation, dynamically controlled tunability, and configurability [1]. Plasmonic lasers offer a possibility of exploring extreme interactions between waves and substances [11], enhancing the spontaneous emission rate in strongly coupled nanocavity arrays [12] and realizing spasing action with huge confinement of light [13]. Another class of optical configurations involving active materials is exploiting the so-called parity-time (PT) symmetry concerning a spatial balance between passivity and activity [14].

C Valagiannopoulos and S A Tretyakov

Problem statement

Stability conditions

Stable system response

The case of a single slab

Conclusions