A device for counting photons includes a detector unit that is configured to generate an detected signal. A switching unit is configured to be impinged upon by the detected signal and to trigger a switching state for each detection pulse so as to generate a state signal. A sampling unit is configured to sample the state signal at a predetermined sampling frequency. A serial-parallel converter unit is configured to parallelize the serially generated sampled data by grouping successive sampled data into a sampled data packet. An evaluation unit is configured to evaluate the binary values of sampled data packets so as to identify a partial counter result indicating the number of switching state changes occurring in the switching unit, and to add partial counter results identified in individual clock cycles.