Coherent control of nonreciprocal optical properties of the defect modes in 1D defective photonic crystals with atomic doping

TL;DR

This paper demonstrates how doping one-dimensional photonic crystals with three-level atoms induces nonreciprocal reflection and absorption in defect modes, controllable via atomic driving fields and dissipation, without relying on PT symmetry or exceptional points.

Contribution

It reveals nonreciprocal optical properties in doped photonic crystals without PT symmetry and shows how to coherently control these effects using atomic parameters.

Findings

Nonreciprocal reflection and absorption in defect modes

Nonreciprocity achieved without exceptional points

Coherent control of nonreciprocity via atomic driving and dissipation

Abstract

We investigate the spectral properties of photonic crystals, lacking parity-time (PT) symmetry, using scattering matrix formalism. We show using the symmetry properties of matrices that a defective photonic crystal, doped with three-level atoms, breaks PT symmetry. For the two defect modes lying in the bandgap region, both the reflection and the absorption become nonreciprocal, while the transmission remains reciprocal. We show that the relevant energy spectra do not exhibit exceptional points, thereby invalidating its necessity to achieve nonreciprocity in reflection and absorption. We further demonstrate how this nonreciprocity can be coherently controlled using the driving field and dissipation rates of the atoms.