Finding and minimizing systematic errors in dual-comb spectroscopy

Abstract With sufficiently high signal-to-noise, several systematic errors become prominent in dual-comb interferometry measurements. This paper reviews several error sources including electrical, photo-detection, amplification and acquisition chain non-linearity. Sources of optical non-linearity such as self-phase modulation, cross-phase modulation and Raman soliton shifting are also covered, as are spectral fringing due to parasitic reflections and back-scattering. The non-linear response of the target sample itself can also be a source of errors. Methods to identify and minimize errors in experimental data are discussed. Good practices, instrument design strategies and tools, such as the dynamic range diagram, are suggested.