Q3MD: single photon sensitive detector for methane gas detection operating at 3µm

为了使英国实现零碳经济，温室气体排放的测量、监管和执行需要迅速扩大。天然气（主要是CH4甲烷）仍然是主要的化石燃料，工业泄漏是温室气体的主要来源。目前，欧盟（EU） ~20万公里高压管道、英国~ 7660公里高压管道和美国~50万公里高压管道，除了地面上的100多处设施外，还缺乏测量方法和设备。该项目旨在开发一种单光子敏感探测器，用于检测工作在3微米的甲烷气体。与商用探测器使用的1.65µm波长相比，在这个波长上可以检测到低得多的甲烷浓度。应用差分吸收激光雷达和时间相关单光子计数技术，可以扩展远程光谱能力，增加距离范围或缩短响应时间；通过进入3µm光谱区域，将低浓度灵敏度提高到50倍。此外，我们可以扩展气体种类，并针对目前无法用SWIR波长解决的其他应用。技术方法是将独特的III-V合金材料开发与Bay Photonics（光学封装），Redwave Labs（控制电子）和QLM（信号处理和光谱分析）的创新科学和工程相结合。目标将是优化固态冷却，使探测器在不依赖斯特林发动机的情况下达到非常低的温度。甲烷应用的项目规范、建模和探测器验证将由渠道合作伙伴QLM领导。总体目标是在3 μ m的单光子/少光子水平上可分辨的探测器，并在台式原型形式中进行评估。

For the UK to reach a zero-carbon economy, the measurement, regulation, and enforcement of greenhouse gases (GHG) emissions needs to rapidly expand. Natural gas (primarily CH4 methane) remains the dominant fossil fuel and industrial leaks are a leading source of GHGs. Currently there are a lack of surveying methods and equipment for the European Union's (EU) ~200,000km of high-pressure pipeline, the UK's ~7,660km of high-pressure pipeline and the ~500,000km of high-pressure pipe-line in the United States in addition to the 100s of above-ground facilities.The project seeks to develop a single photon sensitive detector for methane gas detection operating at 3µm. Methane can be detected at much lower concentrations at this wavelength than at the 1.65µm used in commercial detectors. By applying Differential Absorption Lidar and Time Correlated Single Photon Counting, we can extend the remote spectroscopy capabilities to increase the distance range or decrease the response time; by accessing the 3µm spectral region, low concentration sensitivity is to be increased up to 50-fold. In addition, we can expand the gas species and target other applications are that currently not addressable with a SWIR wavelength.The technical approach is to combine unique III-V alloy material developments with innovative science and engineering at Bay Photonics (optics packaging), Redwave Labs (control electronics) and QLM (signal processing and spectral analysis). The aim will be to optimize solid state cooling to bring the detector to very low temperatures without having recourse to Stirling engines. The project specifications, modelling and detector validation for methane applications will be led by the channel partner QLM. The overall goal is a detector resolvable to single photon/few photon level at 3 µm and evaluated in bench top prototype form.