Metasurface lasers programmed by optical pump patterns
Metasurface lasers offer unprecedented control over light emission, yet their spatial and modal characteristics are typically fixed post-fabrication. Here, we introduce a reconfigurable plasmonic metasurface laser platform in which the lasing area geometry, and thus the emission properties, are dynamically programmed via spatially structured optical pumping. Using hexagonal arrays of silver nanoparticles embedded in dye-doped waveguides, we demonstrate lasing at high-symmetry points of the Brillouin zone, including the K and M points. K-point lasing exhibits spontaneous symmetry breaking (SSB) in relative intensity between degenerate K and K' modes, with no bias induced by pump geometry, even for geometries that explicitly break symmetry. In contrast, M-point lasing allows deterministic control over emission channels via asymmetric pumping. We further show that spatially separated K-point lasers synchronize in phase and amplitude, undergoing SSB in lockstep. A theoretical density matrix approach cast into stochastic differential equations reproduces the observed real- and Fourier-space intensity distributions and SSB behavior. Our findings establish spatially programmable metasurface lasers as a versatile platform for exploring dynamic phenomena in photonic lattices, with potential applications in vortex beam shaping, optical logic, and true random number generation.