| 摘要 |
Provided is a photon detector that enables an APD response by a sinusoidal wave-shaped gate signal and is operable at an arbitrary drive frequency without requiring a special band removing filter. The photon detector of the present invention includes: a sinusoidal wave generator (3) that generates a sinusoidal wave-shaped gate signal; a beam splitter (7) that splits the gate signal; a bias circuit (5) that supplies a signal resulting from superimposing the gate signal which has passed through the beam splitter (7) on a predetermined DC voltage to an avalanche photodiode; a dummy circuit (6) which inputs the gate signal which has passed through the beam splitter (7), and outputs a response signal simulating the avalanche photodiode; a differential amplifier (10) that amplifies a differential input between a response signal from the avalanche photodiode and the response signal from the dummy circuit (6); and a comparator (11) that outputs a photon detection signal when an output from the differential amplifier (10) is equal to or higher than a predetermined threshold voltage. |
