Abstract

The development of laser frequency comb has revolutionized optical frequency metrology in the late 1990s. Its broadband structure of equally spaced spectral lines makes it ideal as a bridge from the optical to the radio frequency domains [1]. Meanwhile, frequency combs also provide numerous remarkable opportunities in other fields such as molecular absorption spectroscopy for which, the frequency comb has triggered new attractive methods, especially in the visible and near-infrared region. For absorption spectroscopy techniques, the sensitivity and bandwidth are limited by the light sources used to probe the interested sample. By using a single frequency laser, high sensitivity but narrow bandwidth spectrum can be achieved. On the contrary, broadband spectral acquisition can be realized at the cost of the sensitivity by using blackbody sources. Laser frequency combs are ideal sources to overcome both disadvantages of traditional light sources for molecular absorption spectroscopy applications [2].

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