Field-resolved detection via electro-optic sampling (EOS) allows for the detection of impulsively excited molecular responses with high quantum efficiency, high dynamic range, and high linearity [1]. This combination, enabled by powerful short-wave mid-infrared gate pulses, makes it an ideal fit for broadband quantitative linear spectroscopy of multiple gases, with a covered concentration range of more than 8 orders of magnitude. This technique brings within reach the fast, label-free, quantitative multivariate detection of volatile organic compounds over the entire known physiologically-relevant molecular landscape. Enhancing the molecular responses in a broadband linear optical resonator additionally boosts the detection limit and further improves the dynamic range by reducing the intensity contrast between the impulsive excitation and the molecular response [2].

[1] Z. Wei, C. Hofer, D. Gerz, N. Karpowicz and I. Pupeza, “Linearity of High-Sensitivity Infrared Electro-Optic Sampling,” Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (2023).

[2] P. Sulzer, M. Högner, A.-K. Raab, L. Fürst, E. Fill, D. Gerz, C. Hofer, L. Voronina, I. Pupeza, “Cavity-enhanced field-resolved spectroscopy,” Nature Photonics 16, 692 (2022).