Photo-detection device, imaging apparatus, and imaging system

Provided are a photo-detection device, an imaging apparatus, and an imaging system. The photo-detection device includes an APD, a current detecting unit to which a signal via a first terminal of the APD is input, a load element connected to a node between the APD and the current detecting unit, a quench signal generating unit to which a signal from the current detecting unit is input and which outputs a quench signal, and a switch connected to a second terminal of the APD and a first wiring line to which first potential is supplied. The node is connected via the load element to a second wiringline to which second potential different from the first potential is supplied, and the quench signal generating unit generates a one-shot pulse signal as the quench signal based on the signal from the current detecting unit and causes the quench signal to be input to the switch. 提供了光检测设备、成像装置和成像系统。种光检测设备包括：APD；经由APD的第端子的信号被输入到的电流检测单元、连接到APD与电流检测单元之间的节点的负载元件、来自电流检测单元的信号被输入到的并且输出猝灭信号的猝灭信号生成单元；和连接到APD的第二端子和第电势被供给到的第布线的开关。节点