PHOTON TO DIGITAL CONVERTERS WITH PICOSECONDS SINGLE PHOTON TIMING RESOLUTION

在从智能手机3D相机和LIDAR到医学成像和量子密码学的各种应用中，能够探测到单个光子的传感器的使用正在不断增加。即使是中微子和暗物质的基础实验也计划使用高达250平方米的低功率单光子探测器。我的技术驱动型研究项目致力于开发一种名为3DdSiPM的突破性加拿大技术。它是由一个光电二极管阵列覆盖并连接到一个先进的电子电路形成的。这种最先进的三维(3D)集成探测器具有许多优势：最大限度地增加光敏面积，独立选择和优化每一层的技术，以及将每个光电二极管1对1耦合到专用电子电路。后者是在测量探测到光子的时间上提供前所未有的精确度的关键。我们的目标是达到10ps的时间分辨率，在光速下，可以以几毫米的精度找到光子源的距离。在这项提案中，我将推进时间-数字转换器(TDC)的开发，使这种时间分辨率能够实现飞行时间正电子发射断层扫描(PET)和量子密钥分发(QKD)。10ps的PET时间分辨率将是一项重大突破，将有助于提高图像质量、降低放射性剂量、个性化治疗并跟踪治疗进展。我们目前的设备已经达到了50ps以下的时间分辨率。这项提议的第一个目标是进一步减少这一点，以达到10ps的目标。我们还将实施一种新颖的TDC架构，在相同或更短的转换时间下提供更好的时序分辨率。我们正在为这一新架构申请专利，并希望将其转让给一家大型电子公司，以获得其无与伦比的性能。利用光子的量子性质进行安全通信是这项提议的另一个重点。在一位量子密码学专家(滑铁卢大学的T.Jennewein)的合作下，我正在设计一种新版本的3DdSiPM，它将利用其高时间分辨率来实现更高效的自由空间量子密钥分配系统。新的体系结构将特别有用，因为它允许降低噪声(更高的定时分辨率)和提高密钥分发率(低转换时间)。我们希望能够将我们的探测器用于我的合作者领导的量子卫星链接项目QEYSSAT的第二个版本。3DdSiPM是与魁北克Bromont的Teledyne DALSA半导体公司合作制造的技术。这为学生在毕业后提供了就业机会，并为他们提供了学习工业半导体工艺和了解世界级行业如何应对挑战的独特机会。

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.