Kinetic Inductance Detectors

Microwave kinetic inductance detector (MKID) provides a way to build large sub-mm instruments as it is possible to read out simultaneously up to a thousand pixels with a single readout line. This type of array, i.e. pair-breaking detectors, are made of superconducting material and it is possible to measure an incoming radiation because it breaks the Cooper pairs inside the superconducting film changing its kinetic inductance. Then, a resonator is connected to every detector and it is possible to measure a change in the kinetic inductance as a change in the resonance frequency and the transmission of the circuit.

In this work we proposed and tested a calibration method based on MKID readout frequency response that could be used in large ground-based sub-millimetre instruments. This method as the advantage that is fast enough to be used in large arrays and it is based on data that are already used to measure KID positions.

In this second work, we instead characterized the level of crosstalk present in a test array above -30 dB.This effect originates from single detectors overlapping in readout frequency, as they are built close in space and frequency to push the multiplexity capability of MKID arrays. We have shown that it is indeed possible to correct for this effect a posteriori.