Optomechanical Shutter Modulated Broad-Band Cavity鈥揈nhanced Absorption Spectroscopy of Molecular Transients of Astrophysical Interest

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• 作者：Anton Walsh ; Dongfeng Zhao ; Wim Ubachs ; Harold Linnartz
• 刊名：Journal of Physical Chemistry A
• 出版年：2013
• 出版时间：October 3, 2013
• 年：2013
• 卷：117
• 期：39
• 页码：9363-9369
• 全文大小：346K
• 年卷期：v.117,no.39(October 3, 2013)
• ISSN：1520-5215

文摘

We describe a sensitive spectroscopic instrument capable of measuring broad-band absorption spectra through supersonically expanding planar plasma pulses. The instrument utilizes incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS) and incorporates an optomechanical shutter to modulate light from a continuous incoherent light source, enabling measurements of durations as low as 400 渭s. The plasma expansion is used to mimic conditions in translucent interstellar clouds. The new setup is particularly applicable to test proposed carriers of the diffuse interstellar bands, as it permits swift measurements over a broad spectral range with a resolution comparable to astronomical observations. The sensitivity is estimated to be better than 10 ppm/pass, measured with an effective exposure time of only 1 s.