Quantum Optics of Non-Hermitian Optical Systems: Propagation of Squeezed State of Light through Dispersive non-Hermitian Optical Bilayers

TL;DR

This paper develops a quantum-consistent framework for dispersive non-Hermitian optical bilayers and studies how they affect the propagation of squeezed light, revealing robustness of quantum features and conditions for accurate effective medium predictions.

Contribution

It introduces a rigorous quantum description of dispersive non-Hermitian bilayers and analyzes their impact on quantum states of light, especially under PT-symmetry.

Findings

Thermally-induced noise has minimal effect at room temperature.

Squeezed states retain nonclassical features after transmission.

Effective medium theory is valid below a critical gain value.

Abstract

We present a rigorous and quantum-consistent description of dispersive non-Hermitian optical bilayers in the framework of the canonical quantization scheme. Then we investigate the propagation of a normally incident squeezed coherent state of light through such media, particularly at a frequency for which the bilayers become parity-time (PT) symmetric. Furthermore, to check the realization of PT-symmetry in quantum optics, we reveal how dispersion and loss/gain-induced noises and thermal effects in such bilayers can affect quantum features of the incident light, such as squeezing and sub-Poissonian statistics. The numerical results show thermally-induced noise at room temperature has an insignificant effect on the propagation properties in these non-Hermitian bilayers. Moreover, tuning the bilayers loss/gain strength, we show that the transmitted squeezed coherent states through the structure can retain to some extent their nonclassical characteristics, specifically for the frequencies far from the emission frequency of the gain layer. Furthermore, we demonstrate, only below a critical value of gain, quantum optical effective medium theory can correctly predict the propagation of quantized waves in non-Hermitian and PT-symmetric bilayers.