Extremely Broadband Stochastic Resonance of Light and Enhanced Energy Harvesting Enabled by Memory Effects in the Nonlinear Response.

We report the first observation of non-Markovian stochastic resonance (SR), and we discover that memory effects in the nonlinearity extremely enlarge the SR bandwidth. Our experimental system is an oil-filled microcavity which, driven by a continuous wave laser, has memory in its nonlinear optical response. Modulating the cavity length while adding noise to the driving laser, we observe a peak in the transmitted signal-to-noise ratio as a function of the noise variance. Through simulations, we reproduce our observations and extrapolate that the SR bandwidth could be ∼3000 times larger in our cavity than in a Kerr-nonlinear cavity. Experiments evidencing this memory-enhanced bandwidth across two decades are presented. As an extension of our results, we numerically demonstrate an order-of-magnitude enhancement in energy harvesting thanks to a nonlinearity with memory.