Large Active Area Superconducting Single-Nanowire Photon Detector With A 100 Mu M Diameter

We demonstrate a large active area superconducting single-nanowire photon detector with a diameter of F100 mu m. The detector was fabricated on a Si substrate with distributed Bragg reflector acting as an optical cavity and coupled with a 105 mu m multi-mode optical fiber. Owing to the extensive kinetic inductor caused by the large sensitive area of the detector, the response waveform exhibited a large overshoot, causing the device to latch with the increasing bias current. By adding a resistor in series with the device, the overshoot was suppressed, and the maximal bias current increased from 25 to 31 mu A. A well-saturated detection efficiency with a maximal value of 65% was achieved at the wavelength of 532 nm. Moreover, the maximal counting rate improved from 1 to 10 MHz.