7,493 research outputs found
ReDIF-perl package, including rech and rr.pm
No full textThis package contains the ReDIF parser and the data checking script rech. The ReDIF parser is a set of Perl modules that allow to create ReDIF data processing tools easy (at least it was the aim). Rech is a checking and error-reporting tool for making sure your data is valid.
New Silicon SPAD technology for enhanced red-sensitivity, high-resolution timing and system integration
No full textOvercoming Pile-up Limitation in Fluorescence Lifetime Imaging
No full textWe present the first compact Time-Correlated Single-Photon Counting single-channel system, capable of overcoming the typical pile-up limitation of Fluorescence Lifetime Imaging. An ultra-fast acquisition is obtained (40 Mcps), along with excellent timing results and negligible distortion
A simple and flexible FPGA based autocorrelator for afterpulse characterization of single-photon detectors
No full textSingle Photon Avalanche Diodes (SPADs) are widely employed for photon counting and timing in a variety of scientific and industrial applications. However they are affected by the afterpulsing effect, which can significantly increase the effective dark count rate of the detector. Being correlated with previous photon pulses, afterpulses can cause sharp distortions in photon correlation experiments. In this paper we exploit autocorrelation to characterize the afterpulsing of SPADs. A FPGA based autocorrelator has been specifically designed to this purpose, featuring a lag-time range from 10ns to more than 10ms, covering a range well beyond the longest expected trapped carrier lifetime
Note: Wide-operating-range control for thermoelectric coolers
No full textA new algorithm for controlling the temperature of a thermoelectric cooler is proposed. Unlike a classic proportional-integral-derivative (PID) control, which computes the bias voltage from the temperature error, the proposed algorithm exploits the linear relation that exists between the cold side's temperature and the amount of heat that is removed per unit time. Since this control is based on an existing linear relation, it is insensitive to changes in the operating point that are instead crucial in classic PID control of a non-linear system
A 4.5 ps precision TCSPC system: design principles and characterization
No full textWith the recent advancements in single-photon detectors, very low-jitter timing systems are required to fully exploit their performance in real applications. In this article, we present the design principles and experimental characterization of a single-channel time-correlated single-photon counting (TCSPC) system, that achieves a jitter down to 4.5 ps FWHM, a peak-to-peak differential nonlinearity of 1.5 % LSB and a count rate of 12 Mcps over a nanoseconds full-scale range. These results have been attained by minimizing the different jitter contributions that are introduced at various levels in the whole timing chain, still without trading them off with the other performance parameters. To the best of our knowledge, this work represents the state-of-the-art performance in case of a full-scale range as large as 12.5 ns
Progress in Quenching Circuits for Single Photon Avalanche Diodes
No full textAbstract—An ever wider variety of applications employ Single
Photon Avalanche Diodes (SPADs) for the detection of faint optical
signals. SPADs are p-n junction biased above the breakdown
voltage and operate in Geiger-mode: each electron-hole pair can
trigger an avalanche multiplication process that causes the current
to swiftly rise to its final value. Additional quenching electronics
is necessary for a SPAD proper working. The additional
electronics characteristics directly affect the system’s obtainable
performances. Different quenching circuits affect the detector performances
in different ways. In the last 15 years there has been
considerable development in the integration of the quenching circuitry
directly with the detector, thus leading to improved performances.
This paper reviews the state of the art of this evolution,
examining and comparing different classes of quenching circuits
and explaining their mode of operations, their advantages and disadvantages
Conceiving and designing high-performance TCSPC systems for biological and quantum imaging
No full text32ps timing jitter with a fully integrated front end circuit and single photon avalanche diodes
No full textExcellent performance of custom technology SPAD detectors have been widely demonstrated in recent years. Low-jitter timing measurements with these detectors require front end electronics able to sense the avalanche current at a very low level when the multiplication process is still confined in a very small area around the photon absorption point. Best in class results (35 ps full width at half maximum) have been obtained with discrete circuits not suitable to be used in densely integrated systems of SPAD arrays required by modern demanding applications. A new fully integrated front end able to read out the avalanche current with a timing jitter as low as 32 ps and suitable to be exploited with SPAD arrays is presented
Near-zero distortion in TCSPC at more than one photon per excitation period: experimental validation
No full textThe time-correlated single-photon counting (TCSPC) technique is widely renowned for its capability of reconstructing rapid and weak light signals with exceptional sensitivity and sub-picosecond timing resolution. Unfortunately, the speed of TCSPC has been historically severely limited to avoid a phenomenon known as pileup distortion. For this reason, the count rate of a classic TCSPC acquisition channel is kept below a few percent of the laser excitation rate (usually 17c-57c). In this work, we experimentally validate a novel, to our knowledge, TCSPC theory recently reported that effectively overcomes such a limitation and finally achieves high-speed operation without distortion. Exploiting a singlephoton avalanche diode (SPAD), in this paper we show how to acquire additional information about the status of the system at run time, and by combining it with the classic TCSPC data histogram, we report how a count rate of approximately 607c of the excitation frequency with near-zero distortion can indeed be achieved with a commercial system
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