Status of Qupid, a novel photosensor for noble liquid detectors

Quartz Photon Intensifying Detector (Qupid) is a novel photosensor based upon hybrid APD technology and with intrinsic radioactivity at least an order of magnitude lower than the presently employed phototubes. The basic concept as well as the status and the prospect of the Qupid are reviewed. The performance of the Qupid as photosensor for the ultraviolet scintillation light of liquid xenon is presented.