PD24 is an international workshop organized jointly by TRIUMF, Simon Fraser University (SFU), the Gran Sasso Science Institute (GSSI) and Princeton University.

PD24 discusses recent progress and developments of photo-sensors including SiPMs, MCPs, APDs, PMTs, hybrid PMTs and digital photon sensors. Furthermore, the workshop covers the multifaceted applications of these technologies across diverse fields such as particle and astroparticle physics, nuclear physics, nuclear medicine, astronomy, and associated instrumentation.