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Fast timing detector is widely used for its picosecond (ps)-level timing resolution, such as Photek-PMT210 with about 50 ps at single-photon electron (SPE) mode. The time characteristics of these types of fast timing photodetectors include rise time, fall time, and electron transit time (TT) of the output signal. The test results of fast timing detector are affected by the light 7 source, the electronic device board, the data acquisition (DAQ) system, and so on. In this article, some comparative test results will be shown and discussed on the factors affecting the performance of fast timing detector. [ABSTRACT FROM AUTHOR]

The photomultiplier tube (PMT) and silicon photomultiplier (SiPM) of small areas have the characteristics of fast time response, suitable for the detection of fast and extremely weak light signals, and the transit time spread (TTS) can be on the picosecond scale. The test system is generally divided into two types: one is the direct acquisition of the waveform (DAW), (DAW such as the high-sampling oscilloscope), and the other is an indirect acquisition of the waveform (IDAW). In this article, both DAW and IDAW will be used to carry out the comparative test of ultra-fast photodetectors to complete the calibration of the performance of ultra-fast detectors and the study on time test systems. This will be helpful for beam experiments to be carried out in the laboratory and provide effective support for the development of domestic fast PMT. [ABSTRACT FROM AUTHOR]

The upgrade of the BESIII end cap time-of-flight (TOF) detector needs to achieve a ~40-ps time resolution level to provide high-performance reference time for beam testing. Fast silicon photomultiplier tubes (SiPMs) have excellent time characteristics and the transition time spread (TTS) can reach tens of picoseconds. Therefore, SiPMs are selected to replace the PMTs in T0 detectors. In this article, we describe that the time characteristics of a fast SiPM and T0 system were studied using a high-speed real-time oscilloscope. In order to obtain the optimal time resolution, coupling techniques of the plastic scintillators and SiPMs were studied. Single-ended coupling between a SiPM and a plastic scintillator can obtain the best time resolution. [ABSTRACT FROM AUTHOR]

Imaging through scattering media holds great promise for biomedical and measurement applications. In this study, we explore a line-scan imaging strategy through strong scattering media based on epipolar constraints. The implemented setup consists mainly of three parts, namely, the laser source, galvo scanner, and the industrial camera. With pre-calibrated system parameters, a set of epipolar lines are easily generated and projected in sequence with the laser and the galvo scanner projection module, while the epipolar lines on the original images corresponding to the illuminating epipolar lines can be effectively extracted. By stitching the extracted epipolar lines together, a whole image less affected by scattering media can be obtained. We validate our approach using a customized letter pattern obscured by a strong diffuser. Experimental result shows that part of the original signal can be recovered whereas almost no information is shown in the comparison image obtained with the conventional method. Furthermore, the proposed system and algorithm are easier to implement than most existing approaches for imaging through scattering media. [ABSTRACT FROM AUTHOR]