Enhanced absorptance of infrared single-photon detectors comprising plasmonic structure integrated NbN pattern on silicon substrate

摘要

Integration of plasmonic structures into superconducting nanowire single-photon detectors (SNSPD) is capable of resulting in enhanced absorptance [1], and makes possible to realize single plasmon detection [2], i.e opens novel avenues also in secure communication and quantum-key computing. In our previous studies we have presented single optical-cavity (OC) and nano-cavity-array integrated (NCAI) SNSPDs, covered by noble metal reflector, and horizontal as well as vertical gold segments integrated into the meandered niobium-nitride (NbN) pattern on sapphire substrate, respectively [1]. Patterns with periodicity (∼600–710 nm) approximating the plasmon wavelength were also inspected to realize parallel electric optimization [1].