AI Article Synopsis
- Optical frequency combs are useful for broadband spectroscopy, providing frequency markers based on a microwave frequency standard, but a discrete distribution limits their effectiveness.
- By combining spectral interleaving with dual-comb spectroscopy in the terahertz (THz) region, researchers managed to set the spectral sampling interval to match the individual mode linewidth, rather than the frequency spacing.
- This new approach enhanced spectral sampling density to 2.5 MHz and improved spectral accuracy to 8.39 × 10(-7), making it a valuable technique for achieving high resolution, accuracy, and broad coverage in THz spectroscopy.
Article Abstract
Optical frequency combs are innovative tools for broadband spectroscopy because a series of comb modes can serve as frequency markers that are traceable to a microwave frequency standard. However, a mode distribution that is too discrete limits the spectral sampling interval to the mode frequency spacing even though individual mode linewidth is sufficiently narrow. Here, using a combination of a spectral interleaving and dual-comb spectroscopy in the terahertz (THz) region, we achieved a spectral sampling interval equal to the mode linewidth rather than the mode spacing. The spectrally interleaved THz comb was realized by sweeping the laser repetition frequency and interleaving additional frequency marks. In low-pressure gas spectroscopy, we achieved an improved spectral sampling density of 2.5 MHz and enhanced spectral accuracy of 8.39 × 10(-7) in the THz region. The proposed method is a powerful tool for simultaneously achieving high resolution, high accuracy, and broad spectral coverage in THz spectroscopy.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898205 | PMC |
| http://dx.doi.org/10.1038/srep03816 | DOI Listing |
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