Cold amplification and fiber coupling of a super-conducting nanowire single-photon detector

Sammanfattning: Single-photon detectors are an essential tool for quantum photonics: one can harness the quantum properties of single photons for quantum communication as well as use the detectors in low illumination applications.Superconducting nanowire single-photon detectors offer high detection efficiency over a widerange of wavelengths, low dark counts, and a good timing resolution compared to single-photonavalanche diodes.The goal of this master thesis is to fabricate SNSPDs and to design a mount for an opticalfiber onto the SNSPD that can be fabricated inside the nanofabrication facility of KTH. Anamplification stage was designed to be placed inside the cryostat to lower the time uncertaintyof the detection peaks. We designed the fiber mount and the SNSPD using only lithographic processes. We designed a low-noise amplification and biasing system inside the cryostat to lower the amplifier noise compared to amplification at room temperature.