Noise-driven localization of collective light in an active synthetic lattice

Noise plays an important role in nonlinear dynamics, giving rise to complex behaviors. While remarkable control over collective multimode states of light has been achieved in nonlinear optical systems driven out of equilibrium, the effect of noise injected through the drive remains understudied. By introducing temporal noise into the modulation of the laser cavity, we create a fluctuating potential along a synthetic frequency lattice formed by the laser modes. As the noise strength increases, the laser emission evolves through three distinct regimes: a broad spectrum, a Gaussian distribution, and finally exponential localization. Time-resolved spectroscopy reveals that transport across the synthetic lattice persists in the Gaussian regime, where it is shaped by the fluctuating potential, but becomes fully suppressed in the localized regime. Our results demonstrate that temporal noise can induce localization in a nonlinear synthetic photonic system, opening new possibilities, to our knowledge, for controlling the dynamics and spectral properties of multimode lasers through engineered modulations.