This low-noise receiver front-end employs a tiny micron-size SIS diode that detects 180-280 GHz signals entering the feed-horn to the left.

Superconducting Sensors are used for low-noise receivers in the far-IR. These include SIS (superconductor-insulator-superconductor) and HEB (hot-electron bolometer) mixers for the front-ends of heterodyne receivers, as well as hot-electron sensors for direct photon-counting. These mixers are being used for ground-based astronomical observations at high-altitude observatory sites. Space flight versions have been incorporated into the Herschel Space Observatory HIFI instrument. The Herschel Space Observatory is a Cornerstone Mission of the European Space Agency. Many of the fabrication steps involved in implementing these sensors have commonality with sensors for other applications, and a group of researchers is currently applying these fabrication techniques for a quantum computing application.