Photodetection device

A photodetection device comprising a plurality of photodetection units each having a light reception region, wherein:

• each of the photodetection unit includes:
• an avalanche photodiode including first and second electrodes and forming the light reception region;
• a first terminal connected to the first electrode and to which a first potential is applied;
• first and second circuit units connected in parallel with each other to the second electrode;
• a second terminal connected to the second electrode via the first circuit unit and to which a second potential is applied;
• and
• a third terminal connected to the second electrode via the second circuit unit and to which a third potential is applied, and
• in each of the photodetection units:
• the first circuit unit includes a resistor and a switch for switching a connection state between the second electrode and the second terminal;
• the switch, the resistor, the second electrode, and the second terminal are connected in series with each other;
• the second circuit unit includes a diode, a capacitor, and a reading circuit including a transimpedance amplifier;
• the diode and the capacitor are connected in parallel with each other to the second electrode;
• the diode includes a third electrode having the same polarity as the first electrode of the avalanche photodiode and a fourth electrode having the same polarity as the second electrode of the avalanche photodiode;
• the third electrode of the diode is connected to the third terminal;
• the fourth electrode of the diode is connected to the second electrode;
• the transimpedance amplifier is connected in series with the capacitor and is connected to the second electrode via the capacitor;
• and
• an absolute value of a potential difference between the first potential and the third potential is smaller than an absolute value of a potential difference between the first potential and the second potential.

A photodetection device comprising:

• an avalanche photodiode including first and second electrodes;
• a first terminal connected to the first electrode;
• first and second circuit units connected in parallel with each other to the second electrode;
• a second terminal connected to the second electrode via the first circuit unit;
• and
• a plurality of photodetection units each including a third terminal connected to the second electrode via the second circuit unit,
• wherein, in each of the photodetection units:
• the first circuit unit includes a resistor and a first switch for switching a connection state between the second electrode and the second terminal;
• the first switch, the resistor, the second electrode, and the second terminal are connected in series with each other;
• the second circuit unit includes a second switch for switching a connection state between the second electrode and the third terminal, a capacitor, and a reading circuit including a transimpedance amplifier;
• the second switch and the capacitor are connected in parallel with each other to the second electrode;
• the second switch, the second electrode, and the third terminal are connected in series with each other;
• and
• the transimpedance amplifier is connected in series with the capacitor and is connected to the second electrode via the capacitor.

A photodetection device comprising:

• an avalanche photodiode including first and second electrodes;
• a first terminal connected to the first electrode;
• first and second circuit units connected in parallel with each other to the second electrode;
• a second terminal connected to the second electrode via the first circuit unit;
• and
• a plurality of photodetection units each including a third terminal connected to the second electrode via the second circuit unit,
• wherein, in each of the photodetection units:
• the first circuit unit includes a resistor and a switch for switching a connection state between the second electrode and the second terminal;
• the switch, the resistor, the second electrode, and the second terminal are connected in series with each other;
• the second circuit unit includes a diode, a capacitor, and a reading circuit including a transimpedance amplifier;
• the diode and the capacitor are connected in parallel with each other to the second electrode;
• the diode includes a third electrode having the same polarity as the first electrode of the avalanche photodiode and a fourth electrode having the same polarity as the second electrode of the avalanche photodiode;
• the third electrode of the diode is connected to the third terminal;
• the fourth electrode of the diode is connected to the second electrode;
• and
• the transimpedance amplifier is connected in series with the capacitor and is connected to the second electrode via the capacitor.