  Numerous applications at the photon-starved regime require a free-space
coupling singlephoton detector with a large active area, low dark count rate
(DCR), and superior time resolutions. Here,we developed a superconducting
microstrip single-photon detector (SMSPD), with a large active area of 260 um
in diameter, a DCR of ~5 kcps, and a low time jitter of ~171 ps, operated at
near-infrared of 1550 nm. As a demonstration, we applied the detector to a
single-pixel galvanometer scanning system and successfully reconstructed object
information in depth and intensity using a time-correlated photon counting
technology.
