  Superconducting strip single-photon detectors offer excellent photon
detection performance and are indispensable tools for cutting-edge optical
science and technologies, including photonic quantum computation and quantum
networks. Ultra-wide superconducting strips with widths of tens of micrometers
are desirable to achieve high polarization-independent detection efficiency
using a simple straight strip. However, biasing the ultra-wide strip with
sufficient superconducting current to make it sensitive to infrared photons is
challenging. The main difficulty is maldistribution of the superconducting
current in the strip, which generates excessive intrinsic dark counts. Here, we
present a novel superconducting wide strip photon detector (SWSPD) with a high
critical current bank (HCCB) structure. This HCCB structure enables suppression
of the intrinsic dark counts and sufficient superconducting current biasing of
the wide strip. We have experimentally demonstrated a polarization-independent
system detection efficiency of ~78% for 1550 nm wavelength photons and a system
dark count rate of ~80 cps using a 20-${\mu}$m-wide SWSPD with the HCCB
structure. Additionally, fast jitter of 29.8 ps was achieved. The
photolithographically manufacturable ultra-wide SWSPD with high efficiency, low
dark count, and fast temporal resolution paves the way toward the development
of large-scale optical quantum technologies, which will require enormous
numbers of ultimate-performance single-photon detectors.
