Multi-photon response of photon-number-resolving superconducting single photon detector

A new photon-number-resolving superconducting single photon detector is fabricated and tested. To integrate the resistors connected to the nanowire, we used one step of electron-beam lithography and four subsequent photolithography steps. A micro cavity was introduced to the structure in order to gain relatively high quantum efficiency. The device fabricated could resolve 6 photons.