Tunable infrared high absorbing polarization independent niobium nitride plasmonic perfect absorber nanowire photodetectors

Abstract

The recent development of photon-based technologies such as quantum cryptography and quantum computing requires high fidelity and fast photodetectors, as well as the ability to detect single photons. One possibility to achieve these goals are superconducting nanowire single photon detectors, utilizing the superconducting-to-normal conducting phase transition. To achieve the required high efficiency, we use resonant plasmonic perfect absorber effects, reaching over 90% polarization-independent absorbance at our target wavelength of 1140 nm. Moreover, the target wavelength can be easily tuned by adjusting the geometry of our detectors. Furthermore, the high absorbance is maintained at oblique incidence, due to the plasmonic perfect absorber principle, and small active areas can be achieved by the high resonant absorption cross-section of plasmonic resonances. We fabricated different tunable, polarization independent plasmonic perfect absorber superconducting nanowire photodetectors and proved their high absorbance and polarization independent response in the wavelength regime around 1140 nm.