New developments on photosensors for particle physics

The needs of experiments in high-energy physics have been for many decades the stimulus for detector developments. For calorimetry, particle identification with ring image Cherenkov detectors, time-of-flight measurements, etc., sophisticated photosensors have been realized. Although photomultiplier tubes are a commercial product since 70 years, an impressive progress has been made recently. The bulky shape turned in a slim design and the quantum efficiency has been increased by almost a factor of 2. During the last 3 decades photodetectors made from semiconductor materials, photodiodes and avalanche photodiodes, have replaced in an increasing number the traditional photomultiplier tubes. The recently developed Geiger-mode avalanche photodiodes with high sensitivity to single photons will accelerate this trend.