Low-power threshold optical bistability enabled by hydrodynamic Kerr nonlinearity of free-carriers in heavily doped semiconductors

TL;DR

This paper demonstrates nanoscale optical bistability at very low power levels by exploiting hydrodynamic Kerr nonlinearities in heavily doped semiconductors, enabled by strong plasmon coupling, paving the way for ultrafast all-optical devices.

Contribution

It introduces a novel low-power optical bistability mechanism using hydrodynamic Kerr nonlinearity in heavily doped semiconductors with plasmon coupling.

Findings

Achieved 1 mW threshold optical bistability.

Demonstrated efficient coupling between surface and bulk plasmons.

Proposed a new approach for ultrafast nonlinear optical devices.

Abstract

We demonstrate nanoscale optical bistability at an exceptionally low power threshold of 1 mW by leveraging Kerr-type hydrodynamic nonlinearities due to the heavily doped semiconductor's free carriers. This high nonlinearity is enabled by a strong coupling between metallic nanopatch surface plasmons and longitudinal bulk plasmons (LBP) that arise in heavily doped semiconductors due to the nonlocality. Through the coupling, an efficient, near-unity conversion of far-field energy into LBP states could be achieved. These findings offer a viable approach to experimentally probe LBPs and lay the groundwork for developing efficient and ultrafast all-optical nonlinear devices.