Strong Localization of Surface Plasmon Polaritons with Engineered Disorder

Area of Science:

• Plasmonics and Nanophotonics
• Condensed Matter Physics
• Materials Science

Background:

• Surface plasmon polaritons (SPPs) are crucial for nanoscale light manipulation.
• Controlling SPP propagation in metallic nanostructures is essential for advanced photonic devices.
• Disorder in nanostructures can significantly alter light-matter interactions.

Purpose of the Study:

• To experimentally demonstrate strong localization of SPPs in metallic nanogratings with short-range correlated disorder.
• To investigate the effect of increasing disorder on SPP confinement and propagation length.
• To explore the potential of disorder engineering for nanoscale light control.

Main Methods:

• Fabrication of metallic nanogratings with varying degrees of short-range correlated disorder.
• Experimental characterization of SPP fields and propagation using optical techniques.
• Analysis of SPP confinement via field decay and autocorrelation functions.

Main Results:

• Demonstrated strong localization of SPPs in the visible regime for the first time.
• Observed significant enhancement of SPP confinement with increased disorder.
• Measured a dramatic shrinkage in effective SPP propagation length due to disorder.
• Verified SPP localization through exponentially decayed fields and vanishing autocorrelation.

Conclusions:

• Short-range correlated disorder induces strong interference and effective permittivity fluctuations, leading to SPP localization.
• Disorder engineering offers a novel approach for manipulating light at the nanoscale.
• Potential applications include random nanolasing, enhanced solar energy harvesting, and strong light-matter interactions.