Researchers at the University of Eastern Finland have uncovered two complementary mechanisms that govern coherence in miniaturized lasers composed of metallic nanoparticle arrays incorporated into an optical gain material, also known as plasmonic lattice lasers.

In one study, published in Laser & Photonics Reviews, they showed that these nanostructures can generate phase-locked ultrafast laser pulse modulation through the synchronization of multiple lasing modes. In a second study, published in ACS Nano, they demonstrated that structures supporting lasing modes with different topologies and polarizations can sustain independent channels without mutual coherence.

Together, these findings establish a unified physical picture of coherence formation in plasmonic lasers and provide new design principles for nanoscale photonic devices.