Integrated signal processing of CMOS Geiger photodiode arrays

Geiger photodiode (GPD) pixels convert the analog photon intensity to a digital count rate and are the basic element in solid-state photomultiplier detectors that are an emerging technology with applications in a variety of nuclear detection and imaging topics. CMOS GPD pixels simplify the integration of signal-processing electronics to enhance the performance and provide a detector-on-a-chip platform. For example, actively quenching the CMOS GPD pixels improves the response time of the pixels to accommodate large event rates and it preserves the digital nature of the binary photon signal, which can simplify the readout electronics and reduce the power consumption of the optical detector. In this work, we describe and characterize the performance of GPD pixels, with integrated active quenching, and examine the effect of active quenching on the performance of the GPD pixel. We demonstrate the integration of on-chip memory and a parallel readout interface for an array of CMOS GPD pixels as progress toward an all digital detector on a chip.