Figure 1
From: Mitigating radiation damage of single photon detectors for space applications
One group of APDs, consisting of two SLiK devices (top), two C30921SH devices (bottom left), and two SAP500S2 devices (bottom right). (The device under the black cap, center, is not discussed in this paper.) The detectors are connected to a PCB with 6 passive quenching circuits, attached to the back of the plate. Bias voltage supply and signal cables can be seen exiting from behind (far bottom).