Superconducting nanowire single photon detectors (SNSPDs)
SNSPDs are highly efficient single photon detectors of visible and near infrared radiation based on superconducting nanowires patterned out of ultrathin films. The current choice of superconducting materials suitable for SNSPD development is limited. Prior to nanostructuring, the as-deposited ultrathin films should provide a continuous surface down to few nanometers thickness. Of all materials for use as SNSPDs studied so far, the only commercially available SNSPD detectors are made of crystalline NbN, NbTiN and amorphous WSi ultrathin films. Particularly important is the possibility for uniform deposition across large areas in order to achieve uniform templates for later detector manufacture.