Plasmonic nanolaser for intracavity spectroscopy and sensorics

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 a significantly more efficient diffusive mixing of dye molecules, which 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 0.07 ppm. This work provides an opportunity to develop applications of intracavity plasmonic laser spectroscopy in biological label detection and other fields.