Nonreciprocity through gain saturation in coupled nanocavities

JM Mai, KW Cheah*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

1 Citation (Scopus)


The nonreciprocal properties of coupled nanocavities incorporating a gain medium were investigated. The proposed coupled nanocavities can be considered as a photonic non-Hermitian heterostructure. Our study shows that the nonlinearity arising from gain saturation plays a crucial role in dictating the transmittance characteristics. With increasing optical excitation intensity, the transmittance for the forward and backward incident directions exhibits a distinct evolution, ultimately leading to broken reciprocity. Furthermore, there exist both stable and metastable states of cavity modes, and these two states coalesce under a strong optical nonlinear effect. The coalescence of these two states can be attributed to the intricate interplay between the gain saturation nonlinearity and mode coupling, thus giving rise to different nonlinear optical characteristics. Our findings offer valuable insights into nonreciprocal phenomena such as optical bistability, and have potential applications for innovative devices with tunable optical properties.

Original languageEnglish
Article number035101
Number of pages6
JournalPhysical Review B
Issue number3
Publication statusPublished - 2 Jan 2024

Scopus Subject Areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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