Nano-optical studies of superconducting nanowire devices for single-photon detection

Heath, Robert M. (2015) Nano-optical studies of superconducting nanowire devices for single-photon detection. PhD thesis, University of Glasgow.

Abstract

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.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: superconducting nanowire, single photon detection, quantum sensor
• Subjects: Q Science > QC Physics; T Technology > TK Electrical engineering. Electronics Nuclear engineering
• Colleges/Schools: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Supervisor's Name: Hadfield, Professor Robert Hugh
• Date of Award: 2015
• Depositing User: Dr Robert Martyn Heath
• Unique ID: glathesis:2015-6132
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 04 Mar 2015 09:26
• Last Modified: 16 Mar 2015 16:21
• URI: https://theses.gla.ac.uk/id/eprint/6132