New trends in vacuum-based photon detectors

Recent progress on vacuum-based photon detectors is reviewed. Even after rapid progress on various solid-state detectors, vacuum-based photon detectors such as photomultipliers still play a significant role in many high-energy experiments where high-speed detection of weak photon signals are critical. The latest development of hybrid devices such as HPD, HAPD, EBCCD and ISPA are reviewed and their advantage over conventional photon detectors is discussed in some detail.