Ultrafast photodetection in an all-silicon chip enabled by two-photon absorption

Abstract

In this letter we theoretically demonstrate that by dramatically enhancing two-photon absorption, all-silicon optical microresonators can act as efficient photodetectors for light at telecom wavelengths. We illustrate this approach with two specific designs based on a ring resonator and a photonic crystal cavity. The proposed scheme is fully compatible with standard silicon complementary metal-oxide-semiconductor processing technology, and thus, could contribute to the development of chip-scale integrated photodetectors based exclusively on silicon.