Limitations of Particle-Based Spasers

TL;DR

This paper develops a comprehensive electromagnetic model for spherical core-shell surface plasmon lasers, revealing the impact of higher order modes and realistic gain rates on device performance.

Contribution

It introduces a fully electromagnetic Mie theory-based model that accounts for realistic gain relaxation rates, improving understanding of particle-based spaser limitations.

Findings

Higher order modes can negate Purcell effect benefits.

Realistic gain relaxation rates are significantly underestimated in previous models.

The model guides better design of more efficient particle-based spasers.

Abstract

We present a semi-classical analytic model for spherical core-shell surface plasmon lasers. Within this model, we drop the widely used one-mode approximations in favor of fully electromagnetic Mie theory. This allows for incorporation of realistic gain relaxation rates that so far have been massively underestimated. Especially, higher order modes can undermine and even reverse the beneficial effects of the strong Purcell effect in such systems. Our model gives a clear view on gain- and resonator-requirements, as well as on the output characteristics that will help experimenters to design more efficient particle-based spasers.