Plasmonic nanolaser for intracavity spectroscopy and sensorics

TL;DR

This paper presents a highly efficient plasmonic nanolaser with a reduced gain volume, demonstrating its effectiveness as a sensitive intracavity sensor for detecting trace dyes, with potential applications in biological detection.

Contribution

The work introduces a novel plasmonic laser design with significantly lowered threshold and gain volume, enhancing intracavity spectroscopy and sensing capabilities.

Findings

Achieved 80x reduction in laser threshold pumping level.

Demonstrated detection of dye at 70 ppb concentration.

Reduced gain medium volume to 400 nL for improved efficiency.

Abstract

We demonstrate intracavity plasmonic laser spectroscopy using a plasmonic laser created from a periodically-perforated silver film with a liquid gain medium. An active zone of the laser is formed by a highly elongated spot of pumping. This results in an 80x decrease in the threshold pumping level; in a significantly more efficient diffusive mixing of dye molecules, which substantially suppresses the effect of their bleaching; and in the ability to reduce the volume of the gain medium to as little as 400 nL. We use this design for a stable plasmonic laser in multiple measurements and demonstrate that it is highly effective as a spaser spectroscopy sensor for intracavity detection of an absorptive dye at 70 ppb. This work provides an opportunity to develop applications of intracavity plasmonic laser spectroscopy in biological label detection and other fields.