摘要： Discrete variable quantum optics stands as one of the most prominent platform for quantum technologies with an increasing number of encouraging out-of-the-laboratory implementations [1]. The quest for competitive quantum photonic systems, compatible with future engineered systems, has promoted huge developments concerning both source and detection devices [2]. To date, a critical point lies in experiments’ operation rates. Time multiplexing technics allow in principle to pump photonic sources at rates on the order of the GHz [3]. However, a strong limitation to ultra-fast operation lies in timing errors at the detection stage. Limited resolution directly affects the quality of any time-correlated single photon counting or quantum state engineering operations [3]. In particular, single photon detector’s timing-jitters lead counts associated with a given optical clock cycle to appear as temporally indistinguishable from those corresponding to neighbouring ones [2]. Fast and accurate time-tagging is mandatory in multiple operations, such as quantum teleportation [1], quantum state engineering [3] and quantum random number generation. In anticipation to further technological advances, as well as in the perspective of promoting novel conceptual developments on existing quantum communication protocols, it is thus of the utmost importance to correctly describe the effects of detectors’ timing performances. In our work, we explicitly address the problem of detection temporal uncertainties by means of an original theoretical model able to describe the temporal behaviour of standard single photon detectors, with no photon-number resolving abilities [2], affected by non negligible timing-jitter and in presence of dead-time [4]. We consider the case of standard ON/OFF detectors, say detectors with no photon-number resolving abilities [2], and we adopt the formalism of positive operator-valued measurements (POVM) [5]. This approach has already been employed to describe detector with photon-number resolving abilities and has been successfully used to experimentally investigate the characteristics of unknown single photon detectors [6]. Our model exploits a multi-mode formalism to describe temporal degrees of freedom to fully describe timing-resolution effects in ON/OFF detectors by a fully operational POVM description, taking into account the effect of dead-time and finite detection efficiency, without any a priori restriction on the number of photons impinging on the detector. We apply our results to the quantitative study of timing-jitter effects in some usual quantum optics experiments, such as direct photon detection, coincidence measurements, and heralded quantum state preparation. As an example, for a time correlation experiment, considering a source of simultaneous twin photons, our model allows expressing explicitly the delay probability density function. As another example, this fully quantum approach allows expressing the density matrix of a single-photon state obtained in a heralded single-photon generation experiment [3], by taking into account the imperfections of the heralding detector. In conclusion, we believe that our work fills a gap in the discussion on practical quantum technologies by providing a full operational POVM description of practical detection stages, with non negligible timing-jitter and in presence of dead-time. Although we mostly provide simple examples involving one or two photons impinging on the detectors, our formalism is capable of describing general experimental situations. We therefore think that these characteristics stand as a valuable help for a better comprehension of the timing-jitter effect in the perspective of developing ultra-fast quantum communication, including when detector’s timing-jitter is not negligible with respect to repetition period.