Title: Spatially correlated loss in superconducting resonator arrays via optical illumination

Superconducting circuits have emerged as a leading platform for quantum computation¹, single photon detection² and quantum sensing³. The performance of these chips depends on their sensitivity to incident radiation, which produces quasiparticles and phonons that propagate throughout the chip^4-6. In this talk, we discuss a milliKelvin scanning laser technique, which allows us to spatially and temporally map the response of superconducting circuits. We apply this technique to an array of superconducting resonators. We monitor the frequency shift of the resonators as the beam spot is varied in both location and intensity. As the beam spot is scanned across the chip we find spatial variation in the resonators’ response for high laser powers. Our results present a testbed that will inform future generations of superconducting chips.