SPAD Applications

Andrada Alexandra Muntean

Towards High-Performance SPAD based detectors for Positron Emission Tomography

Significant effort has been devoted to the development of SPAD-based detectors for positron emission tomography (PET), due to their compactness, suitable spectral range, fast response, and insensitivity to magnetic fields. New PET detectors built using SPAD arrays are capable of detecting photons over a large sensitive area with excellent time resolution. Apart from the photodetectors themselves, the electronics plays a major role, as timing, energy and spatial resolution must be quantified accurately and in a short amount of time. Thus, the detection system in PET is complex, and its functionality and performance must be taken into consideration during the design phase from top-level specifications.


Andrada Alexandra Muntean received her Bachelor’s Degree in Applied Electronics from Politehnica University of Timișoara, Romania, in 2015, and her Master’s Degree in Microelectronics from Delft University of Technology, Netherlands, in 2017. She is presently working towards her PhD in Microelectronics at the Advanced Quantum Architecture Laboratory (AQUA) at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. In 2016, Andrada also undertook an internship at NASA’s Jet Propulsion Laboratory in Pasadena, California, where she developed and characterised a far-ultraviolet spectrometer used for space applications.

The primary focus of her current PhD research is to develop SPAD-based CMOS image sensors and circuitry for biomedical applications; in particular for time-of-flight Positron Emission Tomography.

Dr Claudio Bruschini

SPAD-based detectors and imagers for biophotonics and other sensing applications 

Single-photon avalanche diode (SPAD) arrays are solid-state detectors that offer imaging capabilities at the level of individual photons, with unparalleled photon counting and time-resolved performance. This fascinating technology has progressed at a very fast pace in the past 15 years, since its inception in standard CMOS technology in 2003. A host of architectures have been investigated and a range of biophotonics applications explored, including FLIM, FLIM-FRET, SPIM-FCS, super-resolution microscopy, time-resolved Raman spectroscopy, NIROT and PET. We will review some representative sensors and their corresponding applications. Finally, we will provide an outlook on the future of this fascinating technology.


Dr Claudio Bruschini received his Master’s Degree in High Energy Physics from the University of Genova, and his PhD in Applied Sciences from the Vrije Universiteit Brussel. Dr Bruschini started his professional career in particle physics with the INFN, Italy, working in collaboration with CERN. Soon after, he moved to the EPFL, Switzerland, where he completed substantial work developing landmine detection technologies and humanitarian demining related projects.

He participated in diverse projects in partnership with the EPFL Laboratory in Intelligent Systems, the Lausanne University Hospital, and the EPFL Integrated Circuits Laboratory. He is currently part of the EPFL AQUA group (Advanced Quantum Architectures), holding significant expertise in photonic and electronic quantum devices, single-photon detectors, and biomedical physics.

Dr Giulia Acconcia

Getting fast in single photon measurements: new challenges and ideas with Single Photon Avalanche Diodes

Single Photon Avalanche Diodes (SPADs) are photodetectors that can not only detect single photons, but they can also mark their times of arrival with picosecond precision. These peculiar features opened the way to the successful exploitation of SPADs in a wide variety of applications, like fluorescence lifetime imaging, Earth atmosphere profiling, quantum key distribution and many others. Nowadays, achieving high speed with SPADs is still an open challenge. In this webinar, I will discuss new architectures, ideas, and developed electronics and systems to overcome long-held speed limitations both in photon counting and photon timing.


Dr Giulia Acconcia received her Bachelor’s Degree in Computer Science and Engineering and her Master’s Degree in Electronics Engineering from Politecnico di Milano in 2011 and 2013, respectively. She holds a PhD in Information Technology and is currently a Junior Researcher in the Dipartimento di Elettronica, Informazione e Bioingegneria at Politecnico di Milano.

Her main research interests concern the design and development of integrated circuits required to extract timing information with extremely high performance from Single Photon Avalanche Diodes and to achieve high speed with these sensors in both counting and timing applications. She is involved in many aspects of SPAD-based systems, including modelling, front end design, module development and applications.

Dr Sara Pellegrini

Industrialised SPADs in Deep-submicron CMOS technology and their applications

SPAD devices have only recently been successfully integrated into a fully industrial CMOS process. I will present STMicroelectronics’ SPADs integrated into a 40nm CMOS technology node. This highly advanced node allows for high level integration of the SPAD readout circuit and a time-of-flight system just next to the sensitive array.

Thanks to this technology a miniature direct time-of-flight system was developed capable of multi-zone parallel ranging at long distance, which enables a plurality of applications such as auto-focus assist, LiDAR, gesture recognition and many others.


Dr Sara Pellegrini received her Master’s Degree from the Politecnico di Milano, Italy, in 1999, and her PhD in Physics from Heriot-Watt University, UK, in 2006. After garnering experience in SPAD design and characterisation during her PhD, she joined STMicroelectronics in Edinburgh. Here, she worked her way up from a position as a CMOS Camera Characterisation Engineer in 2006, to SPAD Technology Manager in 2014. From her ample experience in the electrical and optical characterisation of CMOS sensors and the development of SPAD technology, Dr Pellegrini secured a principal role as an Advanced Photonics Pixel Architect in 2017. Her current position within STMicroelectronics to date, Dr Pellegrini is primarily engaged in the research and development of leading-edge photonic pixels.

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