Massively parallel sensing of trace molecules and their isotopologues with broadband subharmonic mid-infrared frequency combs

作者：Muraviev, A. V.; Smolski, V. O.; Loparo, Z. E.; Vodopyanov, K. L.^*

来源：Nature Photonics, 2018, 12(4): 209-+.

DOI：10.1038/s41566-018-0135-2

• OPTICAL PARAMETRIC OSCILLATOR
• MU-M
• COHERENCE PROPERTIES
• FOURIER-TRANSFORM
• SPECTROSCOPY
• SPECTROMETER
• GENERATION
• LASERS

Mid-infrared spectroscopy offers supreme sensitivity for the detection of trace gases, solids and liquids based on tell-tale vibrational bands specific to this spectral region. Here, we present a new platform for mid-infrared dual-comb Fourier-transform spectroscopy based on a pair of ultra-broadband subharmonic optical parametric oscillators pumped by two phase-locked thulium-fibre combs. Our system provides fast (7 ms for a single interferogram), moving-parts-free, simultaneous acquisition of 350,000 spectral data points, spaced by a 115 MHz intermodal interval over the 3.1-5.5 mu m spectral range. Parallel detection of 22 trace molecular species in a gas mixture, including isotopologues containing isotopes such as C-13, O-18, O-17, N-15, S-34, S-33 and deuterium, with part-per-billion sensitivity and sub-Doppler resolution is demonstrated. The technique also features absolute optical frequency referencing to an atomic clock, a high degree of mutual coherence between the two mid-infrared combs with a relative comb-tooth linewidth of 25 mHz, coherent averaging and feasibility for kilohertz-scale spectral resolution.

• 出版日期2018-4