Spatio-spectrally Tailored Multimode Metasurface Lasers in the Visible Range

Spectrally engineered multifrequency nanolasers are highly desirable for on-chip photonics, multiplexed biosensing, and display technologies, yet achieving them within a compact platform remains challenging. Here, we demonstrate multimode lasing from symmetry-broken TiO₂ metasurfaces integrated with an SU8 slab waveguide containing rhodamine 6G. By coengineering guided-mode resonances, surface lattice resonances near Rayleigh anomalies, and quasi-bound states in the continuum, we realize complementary high-Q feedback pathways that overlap with the gain spectrum. The lasing emission direction is tailored through outcoupling via second-order Bragg diffraction and Rayleigh anomaly conditions, supporting both normal and oblique emission. Experiments reveal discrete lasing outputs across ≈100 nm bandwidth (548-648 nm), spanning the full rhodamine 6G emission band, with thresholds as low as ∼7 nJ (35.7 μJ/cm²) and up to four concurrent lasing peaks from a single device. These results establish a metasurface-dye platform for multifrequency and angle-selective lasing, opening new opportunities for compact, multifunctional nanophotonic sources.