Giant Modal Gain, Amplified Surface Plasmon Polariton Propagation, and Slowing Down of Energy Velocity in a Metal-Semiconductor-Metal Structure

TL;DR

This paper demonstrates giant surface plasmon polariton (SPP) gain and slowed energy velocity in a metal-semiconductor-metal structure with highly excited semiconductor, revealing amplified SPP propagation near resonance.

Contribution

It introduces a novel metal-semiconductor-metal structure exhibiting giant SPP gain and energy slowing, advancing plasmonic amplification techniques.

Findings

Giant SPP gain is 1000 times the semiconductor's material gain.

Near resonance, the imaginary part of the wavevector becomes hugely negative.

Energy propagation slows down significantly in the structure.

Abstract

We investigated surface plasmon polariton (SPP) propagation in a metal-semiconductor-metal structure where semiconductor is highly excited to have optical gain. We show that near the SPP resonance, the imaginary part of the propagation wavevector changes from positive to hugely negative, corresponding to an amplified SPP propagation. The SPP experiences a giant gain that is 1000 times of material gain in the excited semiconductor. We show that such a giant gain is related to the slowing down of average energy propagation in the structure