Superconducting nanowire single photon detectors (SNSPDs) are a rapidly maturing detector technology that offer superior performance relative to competing infrared photon counting technologies. The original experimental work presented here explores three novel methods of improving and analysing detector characteristics, employing low-temperature piezoelectric motors at temperatures below 4 K in a closed-cycle cryostat.
Utilizing the low-temperature piezoelectric nanopositioners in tandem with a miniature confocal microscope, this work specifically shows a spatially-separable parallel-wire SNSPD demonstrating one- and two-pixel photon discrimination, with the detector responding more quickly when triggering two pixels. The work demonstrates nanoantenna-coupled SNSPDs, which are simulated, designed, and tested using the same nano-optical setup. In these an increased local absorption into the nanowire is seen at the antennas' resonant wavelengths, enhancing the efficiency of the detector by up to 130 %. Finally, a modified optical setup using a distributed Bragg reflector fibre in place of the microscope to form a tunable cavity around two configurations of SNSPD is demonstrated, improving absorption of the incident light into the nanowire across the whole active area. For these, enhancement in the system detection efficiency of up to 40 % is seen
