Applications of midinfrared quantum cascade lasers to spectroscopy
Applications of midinfrared quantum cascade lasers to spectroscopy
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中红外量子级联激光器在光谱学中的应用
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
D. Weidmann
中科院分区：
文献类型：
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作者：
G. Hancock;G. Ritchie;J. H. Helden;R. Walker;D. Weidmann
我们回顾了脉冲和连续波量子级联激光器在气相物质高分辨率光谱研究中的应用。特别地，脉冲系统用于探测动力学过程的应用以及使用这些快速啁啾设备观察低压样品所固有的快速通道结构被强调。本文还介绍了利用宽脉冲内调谐范围和脉冲时间分辨率对短寿命物质进行宽带吸收光谱和时间分辨浓度测量的方法。为了进行比较，我们还介绍了最近使用连续波外腔量子级联激光系统对低压NO样品进行的亚多普勒Lamb-dip测量。用这种方法量化了该源的稳定性和分辨率。我们发现，当激光以相对较慢的速率调谐时，通过Lamb-dip测量的激光线宽约为2.7 MHz，但随着激光扫描速率的增加，这种转变在30 kHz时被观察到，线宽降至1.3 MHz。利用该源，给出了NO的波长调制光谱。
We review the use of both pulsed and continuous wave quantum cascade lasers in high-resolution spectroscopic studies of gas phase species. In particular, the application of pulsed systems for probing kinetic processes and the inherent rapid passage structure that accompanies observations of low-pressure samples using these rapidly chirped devices are highlighted. Broadband absorber spectroscopy and time-resolved concentration measurements of short-lived species, respectively exploiting the wide intrapulse tuning range and the pulse temporal resolution, are also mentioned. For comparison, we also present recent sub-Doppler Lamb-dip measurements on a low-pressure sample of NO, using a continuous wave external cavity quantum cascade laser system. Using this methodology the stability and resolution of this source is quantified. We find that the laser linewidth as measured via the Lamb-dip is ca. 2.7 MHz as the laser is tuned at comparably slow rates, but decreases to 1.3 MHz as the laser scan rate is increased such that the transition is observed at 30 kHz. Using this source, wavelength modulation spectroscopy of NO is presented.