  Dual-comb spectroscopy in the ultraviolet (UV) and visible would enable broad
bandwidth electronic spectroscopy with unprecedented frequency resolution.
However, there are significant challenges in generation, detection and
processing of dual-comb data that have restricted its progress in this spectral
region. In this work, we leverage robust 1550 nm few-cycle pulses to generate
frequency combs in the UV-visible. We couple this source to a wavelength
multiplexed dual-comb spectrometer and simultaneously retrieve 100 MHz
comb-mode-resolved spectra over three distinct harmonics spanning 380-800 nm.
The experiments highlight the path to continuous dual-comb coverage spanning
200-750 nm, offering extensive access to electronic transitions in atoms,
molecules, and solids.
