High-efficiency and large light-receiving area superconducting nanowire single-photon detector integrated with high-contrast grating

By using a high-contrast grating(HCG,high transmittance>90%)to control the phase shift of incident light,we theoretically designed a novel-structured HCG-integrated superconducting nanowire single-photon detector(HCG-SNSPD)with a high-efficiency and large light-receiving area.Without enlarging the typical single-pixel SNSPD nanowire area(10μm×10μm),the effective detection area is expanded to 115μm,while the absorption efficiency of the nanowire reaches 84.9% at a wavelength of 1550 nm.The effective detection area of HCGSNSPD is increased by 11.5 times compared to that of conventional single-pixel SNSPDs.Moreover,the absorption efficiencies of HCG-SNSPD exceed 70% at wavelengths ranging from 1460 nm to 1650 nm,indicating high-efficiency broadband detection.This study promotes new possibilities for the application of SNSPDs.