Chockalingam Veerappan

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Image sensors capable of resolving the time-of-arrival (ToA) of individual photons with high resolution are needed in several applications, such as fluorescence lifetime imaging microscopy (FLIM), Förster resonance energy transfer (FRET), optical rangefinding, and positron emission tomography. In FRET, for example, typical fluorescence lifetime is of the(More)
In this paper we illustrate the core technologies at the basis of the European SPADnet project (www., and present the corresponding first results. SPADnet is aimed at a new generation of MRI-compatible, scalable large area image sensors, based on CMOS technology, that are networked to perform gamma-ray detection and coincidence to be used(More)
Abstract–Digital SiPMs in the recent past have emerged as a viable low cost alternative to PMTs providing higher granularity and MRI compatibility. The rich dataset generated by digital SiPM sensors have posed a challenge, especially at the system level when a multitude of such sensors are to be used. In this paper we present a sensor network based(More)
Time-of-flight (TOF) information is essential to improve image quality in positron emission tomography (PET) [1]. In a PET system, the TOF information is derived from the scintillation light signal, as detected by the photon detector in use. The timing resolution of a PET system depends, among others, on the intrinsic properties of the detectors as well as(More)
This paper is the first comprehensive presentation of the SPADnet concept. SPADnet is a fully digital, networked MRI compatible time-of-flight PET system, exploiting the speed and integration density of deep-submicron CMOS technologies. The core enabling technologies of SPADnet are a sensor device comprising an array of 8x16 pixels, each composed of 4(More)
With the emergence of large arrays of highfunctionality pixels, it has become critical to characterize the performance non-uniformity of such arrays. In this paper we characterize a 160x128 array of complex pixels, each with a single-photon avalanche diode (SPAD) and a time-to-digital converter (TDC). A study of the array’s non-uniformities in terms of the(More)
Updates from the SPADnet project (fully digital, scalable and networked photonic component for Time-of-Flight PET applications) Edoardo Charbon, Claudio Bruschini, Chockalingam Veerappan, Leo HC Braga, Nicola Massari, Matteo Perenzoni, Leonardo Gasparini, David Stoppa, Richard Walker, Ahmed Erdogan, Robert K Henderson, Steve East, Lindsay Grant, Balázs(More)
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