Optically induced nonreciprocity by a plasmonic pump in semiconductor wires

TL;DR

This paper proposes a novel method for achieving optical nonreciprocity in symmetric semiconductor wires using a plasmonic pump, enabling simple and efficient all-optical diode-like devices without spatial asymmetry.

Contribution

It introduces a new paradigm for optically induced nonreciprocity in symmetric semiconductor wires via plasmonic pumping, bypassing the need for spatial asymmetry.

Findings

Nonreciprocal wavenumber shift with opposite signs for forward and backward signals.

Plasmonic pump induces a cross-nonlinear modulation altering material parameters.

Potential for highly integrated all-optical nonreciprocal devices.

Abstract

In most studies on all-optical diodes spatial asymmetry has been by necessity applied to break Lorentz reciprocity. Here we suggest a paradigm for optically induced nonreciprocity in semiconductor wires which are spatially asymmetry-free and provide a very simple and efficient platform for plasmonic devices. An azimuthal magnetic field induced by a plasmonic pump in the semiconductor wire alters the material parameters and thus results in a cross-nonlinear modulation of the plasmonic signal. Peculiarly the nonlinear wavenumber shift has opposite signs for forward and backward signals whereas Kerr or Kerr-like nonlinearity does not break Lorentz reciprocity in spatially symmetric structures. This principle may open an avenue towards highly integrated all-optical nonreciprocal devices.