title: Dual-comb spectroscopy with a phase-modulated probe comb for sub-MHz spectral sampling.
abstract: We present a straightforward and efficient method to reduce the mode spacing of a frequency comb based on binary pseudo-random phase modulation of its pulse train. As a proof of concept, we use such a densified comb to perform dual-comb spectroscopy of a long-delay Mach-Zehnder interferometer and a high-quality-factor microresonator with sub-MHz spectral sampling. Since this approach is based on binary phase modulation, it combines all the advantages of other densification techniques: simplicity, single-step implementation, and conservation of the initial comb's power.
authors.forename: Nicolas Bourbeau
authors.initials: NB
authors.lastname: Hébert
authors.forename: Vincent
authors.initials: V
authors.lastname: Michaud-Belleau
authors.forename: Sébastien
authors.initials: S
authors.lastname: Magnan-Saucier
authors.forename: Jean-Daniel
authors.initials: JD
authors.lastname: Deschênes
authors.forename: Jérôme
authors.initials: J
authors.lastname: Genest