First detection of air shower Cherenkov light by Geigermode-Avalanche Photodiodes

Geigermode-Avalanche Photodiodes (G-APD) are novel solid state photon detectors with high photon detection efficiency (PDE). They are promising light sensors for very high energy (VHE) ground-based gamma-ray astronomy. We report about first tests to detect Cherenkov photons from cosmic ray air showers. Advantages and limitations of this new light sensor will be discussed.