Long-Path Intracavity Laser Spectrometer for the Measurementof Atmospheric Trace Gases

用于测量大气痕量气体的长光程内腔激光光谱仪

• 批准号: 8961062
• 负责人: J. Barry McManus
• 金额: $ 5万
• 依托单位: Aerodyne Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-01-01 至 1990-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8961062&HistoricalAwards=false
• 关键词: Long; Path; Intracavity; Laser; Spectrometer

There are numerous important atmospheric trace gases with absorption lines in the visible to near ultraviolet. The absorption cross sections for these gases are moderate, but their extremely low concentrations (some below part-per- trillion levels) make them difficult to measure. The Phase I effort will investigate a technique for increasing the sensitivity of intracavity laser absorption spectroscopy, with application to the detection and measurement of trace gases in the atmosphere. The technique places a multipass absorption cell within the resonant cavity of a dye laser. With an intracavity multipass cell, the optical absorption pathlength can be increased by a factor of ten to thirty over the typical values of experimental systems. Intracavity laser spectroscopy may increase sentivity by a factor of ten or more over the previous state of the art. The general goal for Phase I research is to demonstrate and explore the behavior of a tunable dye laser that has an intracavity long-path multi-pass absorption cell. The applicability of such a laser system to the problem, of measuring weakly absorbing atmospheric gases will be evaluated. An atmospheric trace gas measurement instrument based on this system would have many of the properties desired in modern atmospheric chemistry research. These properties include: high sensitivity, fast response, point measurement capability and ruggedness.

有许多重要的大气痕量气体， 可见光至近紫外线的吸收线。 的 这些气体的吸收截面是中等的，但 它们的浓度极低（有些低于每 万亿级）使其难以测量。 第一阶段的工作将研究一种技术， 提高腔内激光吸收的灵敏度 光谱学及其在探测和测量中的应用 大气中的痕量气体。 该技术将一个 染料谐振腔内的多程吸收池 激光器 利用腔内多通池， 吸收路径长度可以增加十倍， 超过实验系统的典型值30。 腔内激光光谱学可以增加灵敏度， 是现有技术的十倍或更多倍。 第一阶段研究的总体目标是证明 并探索可调谐染料激光器的行为， 腔内长光程多程吸收池。 的 这种激光系统对以下问题的适用性 将评估测量弱吸收大气气体。 在此基础上研制了一种大气微量气体测量仪， 系统将具有现代所需的许多特性， 大气 化学研究 这些特性包括：高灵敏度， 快速响应、点测量能力和耐用性。