Life Science Trace Gas Facility, Molecular and Laser Physics, Radboud University, Heyendaalseweg 135, Nijmegen 6525AJ, The Netherlands.
Opt Lett. 2010 Oct 1;35(19):3300-2. doi: 10.1364/OL.35.003300.
An optical parametric oscillator (OPO), pumped by a fiber-amplified diode laser, is combined with off-axis integrated cavity output spectroscopy (OA-ICOS). The cw OPO (power 1.2 W, tunability 3-4 μm, 5 cm(-1) mode-hop-free tuning) has a tuning speed of 100 THz/s, which is ideal for rapid and sensitive trace gas detection. Combined with OA-ICOS, a detection limit of 50 parts per trillion by volume (1×10(12)) of ethane (C(2)H(6)) in nitrogen was obtained in 0.25s at 2997 cm(-1), corresponding to a noise equivalent absorption sensitivity of 4.8×10(-11) cm(-1) Hz(-1/2). The system demonstrates real-time measurements of methane and water in exhaled human breath.
一台由光纤放大二极管激光器泵浦的光参量振荡器（OPO）与离轴集成腔输出光谱学（OA-ICOS）相结合。连续波 OPO（功率 1.2W，调谐范围 3-4μm，5cm^(-1)无跳模调谐）具有 100THz/s 的调谐速度，非常适合快速灵敏的痕量气体检测。与 OA-ICOS 结合，在 2997cm^(-1)处，氮气中乙烷（C(2)H(6)）的检测极限为 50 万亿分之一体积（1×10^（12）），在 0.25s 内获得，对应于 4.8×10^(-11)cm^(-1)Hz^(-1/2)的噪声等效吸收灵敏度。该系统演示了呼出人体呼吸中甲烷和水的实时测量。
