Reservoir computing using a Si-integrated electro-optic oxide: A numerical study

In this numerical study, we investigate the performance of an electro-optic reservoir under the practical constraints of a Si-integrated photonic design enabled by barium titanate, an emergent electro-optic material. Reservoir computing is a compelling neuromorphic architecture due to its natural compatibility with many physical systems. Among available implementations, the electro-optic reservoir, where an optical delay feedback loop serves as the reservoir, offers energy-efficient computation without the need for a separate memory, making its chip-scale implementation very appealing. Barium titanate, with its exceptionally large Pockels' coefficient, has recently enabled significant advances in compact electro-optic modulators, positioning it as a suitable platform for such a chip-scale electro-optic reservoir. We benchmark the performance of the electro-optic reservoir over various tasks and introduce a method of constructing reservoir states that results in significant performance improvement. Furthermore, we demonstrate the superior energy efficiency of barium–titanate-based devices, owing to their very efficient electro-optic modulation. Our results show that compact, energy-efficient electro-optic reservoirs are feasible using barium–titanate-based integrated Si photonic devices.