WSi superconducting nanowire single photon detector with a temporal resolution below 5 ps

Through the use of an impedance matched taper, be we demonstrate a reduction of the noise jitter in WSi SNSPDs to a level below the intrinsic effects, resulting in full-width at half-maximum values of 4.8 ps for 532 nm and 10.3 ps for 1550 nm single photons.