Hamamatsu Photonics C10507 Series Instruction Manual page 8

■ Analog output
The analog output waveform from the MPPC module is adjusted so that a pulse of 100 mV is
obtained at 1 p.e. (equivalent to detecting 1 photon). If two or more photons are detected at the
same timing, then the pulses pile up for output.
MPPC module output waveform measured by oscilloscope
■ Gate time
This is a time width during which the number of input counts is integrated within the MPPC
module.
Gate time is adjustable from a minimum of 1 ms to a maximum of 100 ms.
■ Threshold level
Setting the threshold level to one-half (0.5 p.e.) the height of the 1 p.e. pulse and then using a
frequency counter to count the number of pulses exceeding this threshold level allows measuring
the number of detected photons. The threshold level can be selected from 5 different settings (0.5
p.e. / 1.5 p.e. / 2.5 p.e. / 3.5 p.e. / Disable) on the evaluation software.
MPPC module output waveform measured by oscilloscope
■ Dark count
On the MPPC module, the dark count is defined as the number of counts measured with no light
incident on the MPPC and with the threshold level set at 0.5 p.e.
2p.e.
1p.e.
2p.e.
1p.e.
200mV
100mV
Time→
1.5p.e.
0.5p.e.
Time→
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