High-performance polarization-independent beam splitters and MZI in silicon carbide integrated platforms for single-photon manipulation

Silicon carbide (SiC), containing various intrinsic color centers, is a highly promising optical materials for making monolithic quantum integrated photonic circuits, by combining the single-photon sources with the integrated photonic components in SiC integrated platforms. In this work, we, for the first time, propose compact, efficient and broadband polarization-independent 12 and 22 multimode interference based beam splitters and Mach-Zehnder interferometers (MZI) in SiC integrated platforms for single-photon manipulation. We experimentally demonstrate that these devices exhibit excellent performances. The 12 beam splitter has low average loss of <1 dB, with a wide bandwidth of >100 nm. The 22 beam splitter has low loss of <1.5 dB, with a wide bandwidth of >70 nm. The MZI exhibits high transmission efficiency, with a high classical visibility of 98.3% and 97.6% and a high quantum visibility of 99.0% and 98.7%, for the TE and TM polarized light and photons, respectively.