Photon detector comprises diode connected in series with pulse generator which produces voltage over diode alternating between value lower than throughput voltage and higher than that voltage

摘要

The photon detector comprises a diode (3) connected in series with pulse generator which produces a voltage over the diode alternating between a value lower than the throughput voltage and one higher than the throughput voltage. A capacitance (Ca) is connected in series with the diode, to which capacitance a discharge circuit is connected in parallel. A measurement device measures the voltage over the capacitance. A comparison circuit compares the measured voltage over the capacitance with a predetermined value. The comparison circuit detects a photon when the voltage over the capacitance exceeds the predetermined value. The capacitance in series with the photodiode has a resistance (Ra) in parallel with it. The resistance discharges the capacitance so that a voltage (Vur) over the capacitance goes to zero with constant voltage (Vin). The diode inner capacitance is designated as (Cd). Light (4) as photons with an infrared wavelength falls in against the diode.