A need exists for high-speed single-photon counting optical imaging detectors. Single-photon counting high-speed detection of x rays is possible by using Medipix2 with pixelated silicon photodiodes. In this article, we report on a device that exploits the Medipix2 chip for optical imaging. The fabricated device is capable of imaging at >3000 frames/s over a 256×256 pixel matrix. The imaging performance of the detector device via the modulation transfer function is measured, and the presence of ion feedback and its degradation of the imaging properties are discussed.

Neutrino telescopes such as ANTARES and KM3NeT measure Cherenkov light which is emitted by muons. To reconstruct the track of a muon a time resolution of about 2ns is needed. We have developed a new concept of a hybrid photon detector (HPD) based on the pixelated semiconductor detector Timepix which was designed in the frame of the international Medipix collaboration with support of the EUDET project. We present measurements carried out with a simplified test set-up of an HPD using the Timepix to provide the proof of principle. Time resolution, imaging properties and dark rate were investigated with these measurements.

We present a hybrid photomultiplier concept which employs the pixelated semiconductor detector Timepix for the detection of the photoelectrons. Timepix has been developed by the MEDIPIX collaboration. It comprises 256 × 256 pixels with 55 μ m pixel pitch. By setting an energy threshold it allows to identify single electrons and, therefore, single photons with high resolution. An appropriate electric field between the photocathode and the Timepix configures an image of the photocathode on the Timepix. A high frequency clock enables the determination of the arrival time of each photon. Test measurements and further design considerations are presented.

Hybrid photon detectors equipped with a photocathode and a pixelated anode allow for spatially resolved photo-detection. We present the concept of an asynchronously operating, trigger-free hybrid photon detector with integrated digitization electronics. The front-end electronics is based on the Timepix detector that was developed in the Medipix collaboration. Results from experiments with the Timepix detector exposed to photoelectrons, and from GEANT4 simulations are used to optimize the detector design.

Hybrid photon detectors with pixelated readout electronics allow for photo-detection with a high spatial resolution. We present the concept of a hybrid photon detector based on the 65k-pixel detector “Timepix”. First experiments of the Timepix detector with photo-electrons were carried out and demonstrate that the concept combines good spatial and time resolutions for photo-electron detection. By comparison of the experimental data with GEANT4 simulations we identify the limiting factors for the time resolution: Electron backscattering from the sensor surface and charge-sharing among neighboring pixels in combination with the finite rise time of the preamplifier output pulse. Levers for its improvement in a future dedicated detector design are identified.