Development and construction of the photon counting receiver for the European laser time transfer space mission

We are presenting the work progress and recent results in the development and construction of the photon counting receiver, which is prepared for the European Laser Timing experiment in space. It is an optical link prepared in the frame of the ESA mission Atomic Clock Ensemble in Space. The ultra short laser pulses will be used to synchronize the time scales ground to space with picosecond precision. To minimize the timing biases the photon counting concept of the space born receiver was selected. The requirements put on the photon counting receiver are quite challenging in terms of the long term detection delay stability, wide operation temperature range, extremely high background photon flux and others. Recently, the bread board version of the detector has been constructed and is under extensive test in our labs. The concept and construction will be presented along with the achieved device parameters.