Fatima Mehr, Hausmaninger Thomas, Tomberg Teemu, Karhu Juho, Vainio Markku, Hieta Tuomas, Genoud Guillaume
Opt Lett. 2021 May 1;46(9):2083-2086. doi: 10.1364/OL.420199.
In this Letter, we report on the sub-parts-per-billion-level radiocarbon dioxide detection using cantilever-enhanced photoacoustic spectroscopy. The / ratio of samples is measured by targeting a absorption line with minimal interference from other isotopes. Using a quantum cascade laser as a light source allows for a compact experimental setup. In addition, measurements of sample gases with concentrations as low as 100 parts-per-trillion (ppt) are presented. The Allan deviation demonstrates a noise equivalent concentration of 30 ppt at an averaging time of 9 min. The achieved sensitivity validates this method as a suitable alternative to more complex optical detection methods for radiocarbon dioxide detection used so far, and it can be envisioned for future in situ radiocarbon detection.
在本信函中，我们报告了使用悬臂增强光声光谱法对十亿分比以下水平的放射性二氧化碳进行检测的情况。通过瞄准一条受其他同位素干扰最小的吸收线来测量样品的 / 比值。使用量子级联激光器作为光源可实现紧凑的实验装置。此外，还展示了对浓度低至万亿分之100（ppt）的样品气体的测量结果。在平均时间为9分钟时，阿伦偏差表明噪声等效浓度为30 ppt。所实现的灵敏度验证了该方法是迄今为止用于放射性二氧化碳检测的更复杂光学检测方法的合适替代方案，并且可以设想其用于未来的原位放射性碳检测。
