High-Resolution Measurements of Halogenated Volatile Organic Compounds Using Frequency Comb Fourier Transform Spectroscopy

Halogenated volatile organic compounds (HVOCs) play an important role in the photo-chemistry of the atmosphere, for example in ozone depletion [1] . They are produced naturally in the oceans but are also used in industrial and agricultural applications where they may pose a health-hazard due to their biological effects. Optical detection of these compounds would hence be of great value in, for example, atmospheric monitoring and leak detection in workplaces. Crucial for such detection schemes is access to accurate spectroscopic models, which in turn require high-precision laboratory measurements. Due to the combination of broad spectral coverage and high resolution, optical frequency comb Fourier transform spectroscopy is an excellent tool for providing the necessary spectroscopic data. We use a mid-infrared frequency comb and a Fourier transform spectrometer (FTS) to measure and assign high-resolution spectra of multiple absorption bands of two HVOCs: methyl iodide, CH 3 I [2] , and dibromomethane, CH 2 Br 2 , around 3.3 µm.