As a potent greenhouse gas and an ozone-depleting agent, nitrous oxide (N₂O) plays a critical role in the global climate. Effective mitigation relies on understanding global sources and sinks, which can be supported through isotopic analysis. We present a cross-dispersed spectrometer, coupled with a mid-infrared frequency comb, capable of simultaneously monitoring all singly substituted, stable isotopic variants of N₂O. Rigorous evaluation of the instrument lineshape function and data treatment using a Doppler-broadened, low-pressure gas sample are discussed. Laboratory characterization of the spectrometer demonstrates sub-GHz spectral resolution and an average precision of 6.7 × 10^–6 for fractional isotopic abundance retrievals in 1 s.

中文翻译：

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使用交叉色散光谱仪和中红外频率梳对一氧化二氮同位素进行精密光谱分析。

作为一种强效温室气体和臭氧消耗剂，一氧化二氮 (N ₂ O) 在全球气候中起着至关重要的作用。有效的缓解依赖于了解全球源和汇，这可以通过同位素分析得到支持。我们提出了一个交叉色散光谱仪，加上一个中红外频率梳，能够同时监测 N ₂ O 的所有单取代的稳定同位素变体。使用多普勒展宽的低光谱仪对仪器线形函数和数据处理进行严格评估讨论了压力气体样品。光谱仪的实验室表征证明了 sub-GHz 光谱分辨率和 6.7 × 10 ^–6的平均精度，用于在 1 秒内进行分数同位素丰度检索。