Photon counting timing uniformity–unique feature of the silicon avalanche photodiodes K14

Abstract

The paper reports on detailed tests of active area uniformity of three different single photon avalanche detectors (SPADs). Relative sensitivity, timing jitter, and relative detection delay have been measured for a series of points across the detection area; the resulting spatial profiles have been plotted and analysed. Unique features have been found in the case of silicon-based K14 SPADs: their active area is extremely uniform, especially with respect to the detection delay, in contrast to the remaining two SPADs, which exhibit significant fluctuations of the delay. The perfect uniformity of the K14 SPADs enables the detector to maintain its high temporal resolution of 40 ps FWHM even for large detection areas of 200 µm diameter.