Leaky Integrate-and-Fire Mechanism in Exciton-Polariton Condensates for Photonic Spiking Neurons

This paper introduces a new approach to neuromorphic photonics in which microcavities exhibiting strong exciton-photon interaction may serve as building blocks of optical spiking neurons. The experimental results demonstrate the intrinsic property of exciton-polaritons to resemble the Leaky Integrate-and-Fire (LIF) spiking mechanism. It is shown that exciton-polariton microcavities when non-resonantly pumped with a pulsed laser exhibit leaky integration due to relaxation of the excitonic reservoir, threshold-and-fire mechanism due to transition to Bose-Einstein Condensate (BEC), and resetting due to stimulated emission of photons. These effects, evidenced in photoluminescence characteristics, arise within sub-ns timescales. The presented approach provides means for ultrafast processing of spike-like laser pulses with energy efficiency at the level below 1 pJ per spike.