A method for optimal tuning of microwave kinetic inductance detector arrays under dynamic loading conditions

Microwave kinetic inductance detectors (MKIDs) are increasingly used in ground-based (sub)millimeter-wave astronomy experiments. Two existing challenges to operating detector arrays remain in selecting excitation tones for each MKID where there are hundreds of resonators on the same feedline or network and that will yield the best combination of linearity and sensitivity. This is further complicated when operating arrays at ground-based telescopes, where variations in background loading from the atmosphere can induce significant shifts in MKID resonant frequencies and affect quality factors. We describe a quantitative method for optimal tuning of MKID arrays under dynamic loading conditions. We apply this new readout tuning technique to the 1.1 mm MKID array of the TolTEC camera at the Large Millimeter Telescope, where we incrementally change the readout power applied to investigate its effect. We perform in lab optical characterization of a CCAT Observatory MKID array to investigate optimal tuning under different loading conditions.