Single optical photon detection with a superconducting tunnel junction

Detection of multiple fluorescent labels using superconducting tunnel junction detectors

“…Quantifying the hybridization of labeled nucleic acids ͑probes͒ to immobilized target molecules in microarray format or in cells in situ ideally requires the efficient, artifactfree measurement of several fluorescent spectra simultaneously. 1 Cryogenically cooled superconducting tunnel junction ͑STJ͒ detectors [2][3][4][5][6] developed for astronomy measure the energies of individual optical photons with very low levels of internal background. The operation of a STJ is indicated schematically in Fig.…”

Multiphoton detection using visible light photon counter

“…5 STJs offer single photon detection capability with some wavelength resolution (ϳ45 nm). 4 In this letter, we report the capability of VLPCs of detecting two photons. Such capability can be used for the test of Bell inequality, 6 quantum teleportation experiments 7 and also for the enhancement of the security in quantum cryptography systems.…”

“…High quantum efficiency and low dark counts ͑background noise͒ are considered to be the figure-of-merit in characterizing the performance of a single photon detector. Photomultiplier tubes ͑PMTs͒ and Si avalanche photodiodes ͑APDs͒ 1 have been most widely used, while alternate technologies like solid state photomultipliers ͑SSPMs͒, 2 visible light photon counters ͑VLPCs͒, 3 and superconducting tunnel junctions ͑STJs͒ 4 have recently demonstrated unique capabilities that PMTs and APDs cannot offer. The quantum efficiency required for detection efficiency loophole free test of Bell inequality ͑83%͒ has been realized by the VLPCs (ϳ88%).…”

Experimental and theoretical response of distributed read-out imaging devices with imperfect charge confinement

“…Kinetic inductance detectors ͑KIDs͒, 3 which rely on the change in inductance caused by the excitation of quasiparticles ͑qps͒ by the absorbed photon, can be grouped together on a single signal line by using a different resonance frequency for the read-out resonance circuit for each sensor. Superconducting tunnel junctions 4 ͑STJs͒ measure a photoninduced change in quasiparticle density as a tunnel current across a thin insulating barrier. Being high impedance devices, they are usually read-out with J-FET based charge sensitive preamplifiers, multiplexed read-out is not straightforward and distributed read-out is the more preferred approach.…”