Timing of optical pulses by a photodiode in the geiger mode

The possibility of using a photodiode in the Geiger mode for timing of short light pulses is studied. It is found that the transit time between the light pulse and the electrical response is determined by a reliable exponential growth of electron and hole populations in the depletion layer from the initial level because of the photoionization to a level meeting the detection threshold. This transit time depends on the photon number in the light pulse and has to be measured by an auxiliary linear detector. A device that allows precise timing in the 10-ps range, whatever the photon number beyond 100, is proposed.