Cryogenic Light Detectors for Background Suppression: The CALDER Project

International audience; The CALDER project aims to realize cryogenic light detectors for the next generation of experiments searching for rare events. More in detail, the main application of these devices will be the background suppression in future cryogenic calorimetric experiments searching for neutrinoless double beta decay ($0\nu $DBD). This is the case of CUPID, a next-generation $0\nu $DBD observatory, able to take advantage from particle identification to dramatically reduce the background events. In this contribution, we show the status of the CALDER project. The light sensors developed in this R&D are based on kinetic inductance detector operated in the phonon-mediated approach. Their energy resolution (20 eV), time response ($\upmu $s) and multiplexing capability make them very promising for the future CUPID experiment.