  We report on the characterization of candidate light sensors for use in the
next-generation Imaging Atmospheric Cherenkov Telescope project called
Cherenkov Telescope Array, a major astro-particle physics project of about 100
telescopes that is currently in the prototyping phase. Our goal is to develop
with the manufacturers the best possible light sensors (highest photon
detection efficiency, lowest crosstalk and afterpulsing). The cameras of those
telescopes will be based on classical super-bi-alkali Photomultiplier tubes but
also Silicon Photomultipliers are candidate light sensors. A full
characterisation of selected sensors was done. We are working in close contact
with several manufacturers, giving them feedback and suggesting improvements.
