Overview
Kinetic inductance detectors (KIDs) are planar superconducting resonators that can be used to detect photons. The kinetic inductance and dissipation of the superconducting film depend on the quasiparticle density. When sufficiently energetic photons are absorbed by the KID, Cooper pairs break, causing an increase in the quasiparticle density, a decrease in the resonant frequency, and a decrease in the resonator quality factor. These changes can be detected by monitoring the amplitude and phase of a probe tone that drives the resonator at its nominal resonant frequency. Each KID resonator is given a unique resonant frequency, so hundreds to thousands of detectors in an array can be read out on a single transmission line. The three KID architectures we have been developing are described below.
![](/files/dr-bradley-r-johnson/files/lab-1.jpeg)
Multi-Chroic MKIDs
![](/files/dr-bradley-r-johnson/files/multi-chroic_mkid_module.png)
![]() |
![]() |
![]() |
Dual-Polarization LEKIDs
![](/files/dr-bradley-r-johnson/files/dual-pol_lekids_testing-1024x696.png)
![]() |
![]() |
![]() |
Single-Polarization LEKIDs