Ultralow threshold optical bistability in metal/randomly layered media structure

Area of Science:

• Plasmonics
• Nonlinear Optics
• Materials Science

Background:

• Tamm plasmon polaritons (TPPs) are surface electromagnetic waves at metal-dielectric interfaces.
• Optical bistability is a phenomenon where a system exhibits two different stable output states for a given input.
• Randomly layered media (RLM) offer unique optical properties due to their complex nanostructure.

Purpose of the Study:

• To investigate the optical bistability of Tamm plasmon polaritons (TPPs) at a metal/randomly layered media (RLM) interface.
• To achieve optical bistability with an ultralow switching threshold.
• To analyze the factors influencing the bistability threshold.

Main Methods:

• Fabrication of a metal/RLM structure incorporating a Kerr nonlinear material.
• Experimental measurement of optical bistability.
• Theoretical analysis and numerical simulations to model the observed phenomena.

Main Results:

• Optical bistability was successfully realized in the metal/RLM structure.
• An ultralow switching threshold of 44 kW/cm² was achieved.
• The switching threshold was attributed to field enhancement via resonant transmission in RLM and TPPs.

Conclusions:

• The study demonstrates the potential of metal/RLM structures for nonlinear optical applications.
• The achieved ultralow switching threshold is significant for developing low-power optical devices.
• The bistability threshold is tunable by controlling TPP excitation frequency, metal film thickness, and nonlinear response intensity.