Superconducting optical photon-counting detectors for astronomy

Superconducting detectors are used extensively for astronomy throughout most of the electromagnetic spectrum: submillimetre-wave to X-ray. They have not, however, displaced CCD's in the optical part of the spectrum despite their ability to achieve time-resolved optical photon counting spectroscopy. There is one Group in the US that is working on optical superconducting imaging arrays, and they largely dominate the field. The purpose of the PhD project is to carry out modelling, manufacture, and testing of optical KIDs. We already have devices manufactured, which we have never tested, and so the work can get off to a rapid start. A key part of the project will be to build up the infrastructure needed for testing the optical behaviour of devices at low temperatures. The work will focus on understanding the physics of optical KIDs, particularly with respect to how to achieving high optical efficiencies. We have considerable experience in understanding the the non-equilibrium behaviour of superconductors under microwave and optical illumination , and the dynamical behaviour of superconducting resonators on membranes, and this understanding can be used to underpin our analysis of photon-counting KIDs. The devices we currently manufacture comprise resonators on membranes, and superconducting optical absorbers with integrated backing reflectors, and the PhD will focus on modelling and measuring these devices. In due course, the student will design and manufacture a second generation of devices. This work will be carried out in collaboration with a number of international organisations.