Scintillometry for Practical Quantum Communication

该提案要求购买两个闪烁仪系统，以完成我目前跨越渥太华市的5.4公里自由空间量子通信链路，并将其扩展为量子网络。闪烁仪是一个由两部分组成的系统，一个是发射器单元，它通过链路发射光，一个是测量发射光的强度波动的探测器单元，它可以主动测量穿过自由空间通道的大气湍流强度。大气湍流是一个快速变化的因素，其强度会极大地影响在自由空间链路上运行的量子密码协议的安全性。主动了解从闪烁仪系统获得的大气湍流强度，是有效操作和自由空间链路选择的关键信息，也是量子通信协议安全性与大气条件相关的理论模型的定量和综合建模的关键信息。这些方面对于开发新颖、实用的协议非常重要，这些协议在各种条件下都是健壮和安全的。这对于加拿大人保持加密信息的安全以及量子通信社区来说非常重要，因为关于大气条件的这些细节的知识存在空白。通过获得所需的闪烁仪系统，预计这些研究活动将建立在我们目前的基础上，以创建一个实用的城市量子网络，将渥太华和加拿大定位为量子密码领域的领导者。

This proposal requests the acquisition of two scintillometer systems for the purpose of completing my current 5.4-km free-space quantum communications link across the City of Ottawa and expanding it to a quantum network. A scintillometer is a system consisting of two parts an emitter unit that emits light across the link, and a detector unit which measures the intensity fluctuations of the emitted light which can actively measure the atmospheric turbulence strength across a free-space channel. Atmospheric turbulence is a rapidly varying factor, and its strength can greatly affect the security of quantum cryptographic protocols operated across free-space links. Actively knowing the atmospheric turbulence strength, obtained from a scintillometer system, is a crucial piece of information for both the effective operation and choice of free-space links, but also for the quantitative and comprehensive modelling of theoretical models correlating the security of quantum communication protocols to atmospheric conditions. These aspects are important for the development of novel, practical protocols that are robust and secure in a wide range of conditions. This is important for Canadians to keep their encrypted information secure and the quantum communications community as there is a gap in knowledge concerning these details about atmospheric conditions. Enabled by the acquisition of the requested scintillometer systems, it is anticipated that these research activities will build upon our current foundations for creating a practical urban quantum network, positioning Ottawa and Canada as a leader in the field of quantum cryptography.