SBIR Phase I: Cavity-Enhanced Direct Frequency Comb Spectroscopy: A Multi-Species Technology for Fingerprinting Fugitive Emissions

这个小企业创新研究第一阶段项目将是开发第一个基于腔增强直接频率梳谱（CE-DFCS）的商用分析仪的关键一步。这项新技术克服了传统的窄带、高特异性、基于激光的技术和宽带、低分辨率、多物种方法之间的鸿沟。CE-DFCS在单一仪器中提供了这两类的优点，开辟了一个可能性领域。对于逸散排放监测的拟议应用，CE-DFCS将有助于获得有价值的数据，以更好地了解和减少农业活动和天然气泄漏产生的甲烷排放。后一个问题是一个巨大的问题，不仅会加速气候变化，还会造成数百万美元的经济损失，并对公共安全构成威胁。这些问题将推动这类监测技术的市场增长：目前约5000万美元的市场可能在五年内翻一番。除了这种应用之外，CE-DFCS固有的多功能性和能力也将使其广泛适用于其他行业，例如实时过程控制和化学计量学，它最终可以取代傅立叶变换光谱仪和气相色谱仪等复杂仪器。这个项目的智力价值在于找到一条途径，使CE-DFCS在气候研究和减轻污染方面的便携式精确测量具有足够的可靠性。这项技术代表了当前光谱技术的重大变化，如可调谐二极管激光，腔衰荡和傅立叶变换光谱。由此产生的仪器将使研究人员和工业界能够更精确地识别和量化来自管道、井、农场、垃圾填埋场、森林、沼泽和其他来源的排放。虽然学术界的实验已经证明CE-DFCS在这一应用中具有巨大的潜力，但很少有工作关注于现场使用所需的鲁棒性。第一阶段的研究将重点关注频率梳和光学增强腔之间耦合的长期稳定性的关键需求，该耦合必须不受振动和环境变化的影响，其程度要比之前证明的高得多。因此，研究目标是合理设计、集成和优化具有商业光学腔的电子器件，以实现稳健的自优化梳腔耦合。通过所提出的设计和优化的控制参数和反馈机制，期望具有良好的长期稳定性和抗振性。获得的结果将作为进一步开发和优化CE-DFCS用于商业应用的基础。

This Small Business Innovation Research Phase I project will be a pivotal step towards the development of the first commercial analyzer based on Cavity-Enhanced Direct Frequency Comb Spectroscopy (CE-DFCS). This new technique overcomes the traditional divide between narrow-band, highly specific, laser-based techniques and broadband, low-resolution, multi-species methods. CE-DFCS offers the advantages of both categories in a single instrument, opening a realm of possibilities. For the proposed application of fugitive emissions monitoring, CE-DFCS will help to obtain valuable data to better understand and mitigate methane emissions from both agricultural activities and natural gas leakage. The latter issue represents an enormous problem that not only accelerates climate change, but also causes millions of dollars in economic losses and represents a risk to public safety. These issues will drive an increasing market for this type of monitoring technology: the approximately $50 million current market could potentially double within five years. Beyond this application, the versatility and capability inherent in CE-DFCS will also make it widely applicable to other industries, e.g. for real-time process control and chemometrics, where it can ultimately displace complex instruments such as Fourier transform spectrometers and gas chromatographs.The intellectual merit of this project is finding a pathway to making CE-DFCS sufficiently robust for portable precision measurements in climate research and pollution mitigation. This technology represents a major change from present day spectroscopic technologies, such as Tunable Diode Laser, Cavity Ring-Down, and Fourier Transform Spectroscopy. The resulting instrument will allow researchers and industry to more precisely identify and quantify emissions from pipelines, wells, farms, landfills, forests, swamps, and other sources. While experiments from academia have demonstrated that CE-DFCS has great potential for this application, little work has focused on robustness necessary for field use. Phase I research will focus on the critical need for long-term stability in the coupling between the frequency comb and the optical enhancement cavity, which must be impervious to vibrations and environmental changes to a much higher degree than previously demonstrated. Therefore, the research objective is to properly design, integrate and optimize the electronics with a commercial optical cavity, for robust and self-optimizing comb-cavity coupling. With the proposed design and optimized control parameters and feedback mechanics, excellent long-term stability and vibration resistance is anticipated. The obtained results will serve as a basis to further develop and optimize CE-DFCS for commercial applications.