Toward theoretically limited SPP propagation length above two hundred microns on ultra-smooth silver surface

TL;DR

This paper demonstrates an ultra-smooth, single-crystalline silver film that enables surface plasmon-polariton waves to propagate over 200 microns, reaching the theoretical limit for silver-based media.

Contribution

It introduces an atomically-flat silver film that significantly extends SPP propagation length to the theoretical maximum, surpassing previous experimental results.

Findings

SPP propagation length of 200 microns on the silver surface

Propagation length is twice as long as previous experimental results

Achieves the theoretically limited SPP propagation length for silver films

Abstract

We demonstrate the optical medium for surface plasmon - polariton waves (SPP) propagation with ultra low losses corresponding to the theoretically limited values. The unique element of the optical medium is an atomically-flat single-crystalline silver thin film which provides extremely low losses. The SPP excited on the surface of such thin films (at 780 nm) is characterized by a SPP propagation length equals to 200 um, which is twice longer than previously reported experimental results and corresponds to theoretically limited values for silver films.