Figure 2
From: Repeated radiation damage and thermal annealing of avalanche photodiodes
Schematic of the detector characterization setup. Si APDs, housed in a detector module, are placed inside a passive cooler box filled with dry ice acting as a heat sink. The detector power and control unit (DPCU) maintains detector bias voltages and controls thermal conditions via detector and bracket TECs. Fibers guide optical pulses from a laser to the detectors and to an optical power meter for reference measurement via a fiber beam splitter. A fiber bridge coupling into a multi-core fiber is used to split the laser light between each of the detectors. The output from the detectors is either measured on an oscilloscope or time-tagged and recorded on a computer