Magnetic on-off switching of a plasmonic laser

TL;DR

This paper demonstrates magnetic-field control of plasmonic laser emission using Co/Pt nanodots, enabling external modulation of lasing action through magnetization reversal, which opens new avenues in topological photonics.

Contribution

It introduces magnetic control of plasmonic nanolasers via magnetization of Co/Pt nanodots, a novel method for external modulation of laser emission.

Findings

Magnetization reversal switches lasing and non-lasing states.

Circular polarization reveals angle-dependent lasing transition.

Magnetic effects influence light emission in the lasing regime.

Abstract

The nanoscale mode volumes of surface plasmon polaritons have enabled plasmonic lasers and condensates with ultrafast operation. Most plasmonic lasers are based on noble metals, rendering the optical mode structure inert to external fields. Here, we demonstrate active magnetic-field control over lasing in a periodic array of Co/Pt multilayer nanodots immersed in an IR-140 dye solution. We exploit the magnetic nature of the nanoparticles combined with mode tailoring to control the lasing action. Under circularly polarized excitation, angle-resolved photoluminescence measurements reveal a transition between lasing action and non-lasing emission as the nanodot magnetization is reversed. Our results introduce magnetization as a means of externally controlling plasmonic nanolasers, complementary to the modulation by excitation, gain medium, or substrate. Further, the results show how effects of magnetization on light that are inherently weak can be observed in the lasing regime, inspiring studies of topological photonics.