Cavity-enhanced spontaneous Raman scattering was investigated as a means of simple and inexpensive isotopic water analysis. A multimode blue laser diode equipped with a feedback-generating multipass cavity provided a 100-fold Raman enhancement at a pump linewidth of 3.5 cm⁻¹. Samples containing trace amounts of ¹H²H¹⁶O were probed at deuterium-hydrogen concentration ratios ranging from 157 parts-per-million (local seawater) down to 8 parts-per-million (deuterium depleted water). All measurements were performed in argon or dried air at atmospheric pressure at ¹H²H¹⁶O concentrations nearing 100 parts per billion with an uncooled camera at exposure times as short as a few minutes.

中文翻译：

---

使用多通道腔拉曼散射对水蒸气进行同位素痕量分析

作为一种简单且廉价的同位素水分析手段，研究了腔增强自发拉曼散射。配备有反馈生成多通腔的多模蓝色激光二极管在 3.5 cm ^-1的泵浦线宽下提供了 100 倍的拉曼增强。对含有痕量¹ H ² H ¹⁶ O 的样品进行了探测，其氘氢浓度比范围从百万分之 157（当地海水）到百万分之 8（贫氘水）。所有测量均在氩气或大气压下的干燥空气中进行，温度为¹ H ² H ¹⁶使用未冷却的相机，曝光时间短至几分钟，O 浓度接近十亿分之 100。