PHOTON TO DIGITAL CONVERTERS WITH PICOSECONDS SINGLE PHOTON TIMING RESOLUTION

点击翻译按钮获取中文摘要

The use of sensors capable of de detecting a single photon is constantly increasing in applications ranging from smartphone 3D cameras and LIDARs to medical imaging and quantum cryptography. Even neutrino and dark matter fundamental experiments are planning the use up to 250 m2 of low power single photon detectors. My technology-driven research program is dedicated to the development of a groundbreaking Canadian technology called 3DdSiPM. It is formed by a photodiode array overlaid on and connected to an advanced electronic circuit. This state-of-the-art 3-dimensionnaly (3D) integrated detector has many advantages: maximizing photosensitive area, choosing and optimizing each layer's technology independently, and coupling 1-to-1 each photodiode to a dedicated electronic circuit. The latter is a key to provide unprecedented precision on the measurement of the time at which a photon was detected. Our goal is to reach a timing resolution of 10 ps which at the speed of light allows to find the distance of the photon source with a precision of a few millimeters. In this proposal, I will advance the development of time-to-digital converters (TDC) that allow such timing resolution to enable time-of-flight positron emission tomography (PET) and quantum key distribution (QKD). A timing resolution of 10 ps in PET will be a major breakthrough that will allow improving image quality, reducing the radioactivity dose, personalizing treatments and tracking treatment evolution. Our current devices now reach below 50 ps timing resolution. A first goal of this proposal is to reduce this further to reach the 10 ps goal. We will also implement a novel TDC architecture that offers better timing resolution with the same or shorter conversion time. We are in the process of patenting this new architecture and hope to transfer this to a major electronics company for its unmatched performances. Secure telecommunications using the quantum nature of photons is another focus of this proposal. With the collaboration of an expert in quantum cryptography (T. Jennewein, U. of Waterloo), I'm designing a new version of 3DdSiPM that will leverage its high timing resolution to enable a more efficient free-space QKD system. The new architecture will be particularly useful as it allows to reduce noise (higher timing resolution) and to increase key distribution rates (low conversion time). We hope to be able to use our detectors in the second version of the quantum satellite link project QEYSSAT led by my collaborator. The 3DdSiPM is a technology fabricated in collaboration with Teledyne DALSA Semiconductor (Bromont, Quebec). This offers students employment after graduation and gives them a unique opportunity to learn industrial semiconductor processing and to see how world class industries handle challenges.