title: Unobtrusive interferometer tracking by path length oscillation for multidimensional spectroscopy.
abstract: We track the path difference between interferometer arms with few-nanometer accuracy without adding optics to the beam path. We measure the interference of a helium-neon beam that copropagates through the interferometer with midinfrared pulses used for multidimensional spectroscopy. This can indicate motion, but not direction. By oscillating the path length of one arm with a mirror on a piezoelectric stack and monitoring the oscillations of the recombined helium-neon beam, the direction can be calculated, and the path delay can be continuously tracked.
authors: Laboratoire d'Optique et Biosciences, Ecole Polytechnique Centre National de Recherche Scientifique, 91128 Palaiseau, France.
authors: Kevin F
authors: KF
authors: Lee
authors: Adeline
authors: A
authors: Bonvalet
authors: Patrick
authors: P
authors: Nuernberger
authors: Manuel
authors: M
authors: Joffre
mesh_terms: D004867:Equipment Design; D005583:Fourier Analysis; D006371:Helium / Q000737:chemistry; D007368:Interferometry / Q000379:methods*; D009356:Neon / Q000737:chemistry; D055095:Optics and Photonics; D009991:Oscillometry / Q000379:methods*; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D006371:Helium; D009356:Neon