Spontaneous Parametric Down‐Conversion in 4H‐SiC Integrated Platform

Abstract

4H‐silicon carbide (SiC) has recently emerged as a promising material for nonlinear photonic integrated circuits, thanks to its low loss, wide bandgap, as well as strong second‐order () and third‐order () nonlinearities. Though its unique crystal structure allows versatile processes, spontaneous parametric down‐conversion (SPDC) still remains unrealized. In this work, photon‐pair generation in a 4H‐SiC‐on‐insulator integrated platform is demonstrated through modal‐phase‐matched type‐I SPDC. Furthermore, type‐0 and type‐II nonlinear interactions are shown in 4H‐SiC waveguides, thus highlighting the potential to exploit diverse phase‐matching mechanisms on this platform. These results underscore the potential of 4H‐SiC for advancing the development of integrated quantum photonics in the realms of quantum information processing and quantum communication.