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Single-photon detection and timing has attracted increasing interest in recent years due to their necessity in the field of quantum sensing and the advantages of single-quanta detection in the field of low-level light imaging. While simple bucket detectors are mature enough for commercial applications, more complex imaging detectors are still a field of research comprising mostly prototype-level detectors. A major problem in these detectors is the implementation of in-pixel timing circuitry, especially for two-dimensional imagers. One of the most promising approaches is the use of voltage-controlled ring resonators in every pixel. Each of these runs independently based on a voltage supplied by a global reference. However, this yields the problem that the supply voltage can change across the chip which, in turn, changes the period of the ring resonator. Due to additional parasitic effects, this problem can worsen with increasing measurement time, leading to drift in the timing information. We present here a method to identify and correct such temporal drifts in single-photon detectors based on asynchronous quantum ghost imaging. We also show the effect of this correction on recent quantum ghost imaging (QGI) measurement from our group. [ABSTRACT FROM AUTHOR]

In this letter, we present the timing performance of an optimized red-enhanced single-photon avalanche diode (RE-SPAD) manufactured with a fully custom fabrication process. The detector has been characterized with an external CMOS front end circuit able to read out the RE-SPAD avalanche current and provide the timing information with state-of-the-art jitter. In particular, the careful minimization of the RE-SPAD capacitive parasitics, along with the transimpedance architecture and the gigahertz bandwidth of the front end circuit, allowed the achievement of a timing jitter as low as 83 ps full width at half maximum that increases only up to 103 ps for a detection threshold as high as 600 mV. This feature makes it possible to implement high-threshold detection systems insensitive to the electrical disturbances coming from other SPADs integrated in the same chip, demonstrating that the extension of this work to multichannel systems is feasible. [ABSTRACT FROM AUTHOR]

In recent years, single-photon timing techniques have been employed in a steadily increasing number of applications. Most of these applications require high detector performance in terms of noise, photon detection efficiency, time resolution, and number of pixels operating in parallel. The detectors best fitting these requirements are single-photon avalanche diode (SPAD) arrays built in custom technology, although the systems based on such detectors are limited to a few pixels. In this paper, we present a novel read-out circuit, developed in a 0.18- $\mu $ m high voltage-CMOS technology, for the detection of the SPAD avalanche current: the designed circuit is based on a 2.2-GHz bandwidth integrated transimpedance amplifier, followed by a low-pass filter, to reduce crosstalk, and by an integrated comparator. The pick-up circuit has a total power dissipation of 1.1 mW, occupies an overall area of 15500 \mu $ \mathrm{m}^{2} and shows a time resolution down to 48 ps and a negligible crosstalk between two different pixels. All these features can open the way to the development of large SPAD arrays, characterized by a performance comparable with that of the single-pixel structures. Moreover, the good agreement between the simulated and the measured resolution (with a 14% maximum error) makes the future improvement of the evaluated performance possible. [ABSTRACT FROM AUTHOR]