Mid-infrared single- and multi-frequency coherent sources for high-resolution molecular spectroscopy

The mid-infrared portion of the electromagnetic spectrum is of particular interest due to the abundance and intensity of simple molecule absorption lines that fall in this spectral region. On the other hand, laser technologies are here still in development. This thesis, entitled Mid-infrared single- and multi-frequency coherent sources for high-resolution molecular spectroscopy, contains a collection of experiments aimed to the generation and the control of coherent mid-infrared radiation for high-resolution molecular spectroscopy purposes. The proposed sources are based on non-linear generation and on quantum cascade lasers. The initial approach consisted in generating single-frequency mid-infrared radiation, eventually referenced to a near-infrared frequency comb. Subsequently, approaches to generate and control frequency combs directly in the mid infrared have been implemented.