  We present the characterization of two-dimensionally arranged 64-pixel NbTiN
superconducting nanowire single-photon detector array for spatially resolved
photon detection. NbTiN films deposited on thermally oxidized Si substrates
enabled the high-yield production of high-quality SSPD pixels, and all 64 SSPD
pixels showed uniform superconducting characteristics. Furthermore, all of the
pixels showed single-photon sensitivity, and 60 of the 64 pixels showed a pulse
generation probability higher than 90% after photon absorption. As a result of
light irradiation from the single-mode optical fiber at different distances
between the fiber tip and the active area, the variations of system detection
efficiency in each pixel showed reasonable Gaussian distribution to represent
the spatial distributions of photon flux intensity.
