title: Terahertz achromatic quarter-wave plate.
abstract: Phase retarders usually present a strong frequency dependence. We discuss the design and characterization of a terahertz achromatic quarter-wave plate. This wave plate is made from six birefringent quartz plates precisely designed and stacked together. Phase retardation has been measured over the whole terahertz range by terahertz polarimetry. This achromatic wave plate demonstrates a huge frequency bandwidth (upsilonmax/upsilonmin approximately 7), and therefore can be applied to terahertz time domain spectroscopy and polarimetry.
authors.affiliation: Laboratoire d'Optique et Biosciences, CNRS UMR 7645, INSERM U696, Ecole Polytechnique, Palaiseau, France.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Masson
authors.forename: Guilhem
authors.initials: G
authors.lastname: Gallot