Topologically-protected optical bistability based on two-dimensional photonic crystal L6 nanocavity dimer array.

Area of Science:

• Photonics
• Condensed Matter Physics
• Nonlinear Optics

Background:

• Photonic crystals offer unique light manipulation properties.
• Topological edge states exhibit enhanced field localization.
• Optical bistability is crucial for nonlinear optical devices.

Purpose of the Study:

• To numerically investigate optical bistability in a 2D photonic crystal L6 nanocavity dimer array.
• To compare the performance of topological and trivial nanocavities.
• To assess the robustness of topological cavities against defects.

Main Methods:

• Numerical simulations of a 2D photonic crystal L6 nanocavity dimer array.
• Configuration under the Su-Schrieffer-Heeger model.
• Introduction of defects and interferences to test robustness.

Main Results:

• Localized electric fields in topological edge states lead to enhanced nonlinear phenomena like optical bistability.
• Topological cavities show superior optical bistable performance (low threshold power, high switching contrast) compared to trivial cavities.
• Topological cavities demonstrate robustness against introduced defects.

Conclusions:

• Topological photonic crystals provide a novel platform for achieving robust optical bistability.
• The enhanced performance of topological cavities opens avenues for advanced photonic devices.
• This work facilitates the integration of optical bistable devices into photonic integrated circuits and photonic neural networks.