PHOTON DETECTION CIRCUIT AND NOISE ELIMINATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method of detecting and eliminating noise caused by a dark current and to provide a photon detection circuit employing the same.

SOLUTION: An identification circuit 41 compares a current signal s50 resulting from converting a current flowing through an avalanche photodiode APD into a voltage with a threshold VTH2for detecting an initial very small current to provide an output of a first identification signal s60 and a signal s62 resulting from delaying the signal s60 by a time τ to a reset terminal of a D-FF circuit 60. An identification circuit 40 compares the current signal s50 with a threshold VTH1(>VTH2) to provide an output of a second identification signal s53 to a data terminal of the D-FF circuit 60. The D-FF circuit 60 controls an output of a photon detection signal depending on a temporal context between a reset signal s62 and a data signal s53.

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