Engineering Innovation Makes Quantum Technology More Reliable
Evan Clifford, E’26, electrical engineering, and ECE Assistant Professor Marco Colangelo published their research on “High polarization extinction superconducting nanowire single-photon detectors through grating engineering” in the Journal of Optics. They presented a new architecture for single-photon polarization discrimination, which achieves high detection efficiency while reducing fabrication complexity compared to existing designs. This research was funded by the Spring 2025 AJC Merit Research Scholarships.
Abstract:
Polarization-resolved single-photon detection is a key requirement for advanced quantum photonic applications, including polarization-encoded quantum communication and polarimetric imaging. Although various superconducting nanowire single-photon detector architectures have demonstrated high polarization extinction ratios, concurrently achieving high optical absorption efficiency remains a nontrivial challenge. We propose a compact detector design in which a superconducting nanowire is embedded within a polarization-sensitive silicon grating cavity. The cavity supports distinct longitudinal resonances depending on the incident polarization, thereby enabling selective enhancement of absorption for the desired polarization state. Notably, this configuration introduces minimal fabrication complexity compared to conventional SNSPDs, as the grating cavity can be etched concurrently with the nanowire meander. In numerical simulations, our detector design achieves an absorption efficiency of up to 89.96% and a polarization extinction ratio of , with a fill factor of just 7%. These results represent a significant advancement toward realizing high-performance, polarization-discriminating single-photon detectors.