title: Precision measurement of the refractive index of air with frequency combs.
abstract: We report an experimental method for high-precision refractive index measurement using a Michelson interferometer setup with a femtosecond optical frequency comb as the light source. We demonstrate this technique by measuring the refractive index of air, under different pressures, inside a 29 m multipass cell. Both spectral and temporal interferograms are recorded. The method has a sensitivity of 6.2 x 10(-9) and a standard error of 7.4 x 10(-8) at fixed parameters (pressure and temperature). The possible variation of the density factor from the Lorentz-Lorenz equation is also discussed.
authors.affiliation: Institute of Optics, Information and Photonics, Max-Planck Research Group and University Erlangen-Nuremburg, 91058 Erlangen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: Z H
authors.initials: ZH
authors.lastname: Lu
authors.forename: L J
authors.initials: LJ
authors.lastname: Wang