title: A terahertz time-domain spectrometer for simultaneous transmission and reflection measurements at normal incidence.
abstract: We present a versatile terahertz time-domain spectrometer which allows reflection measurements at normal incidence and double pass transmission measurements in a single experimental setup. Two different modes for transmission measurements are demonstrated for precise measurements of transparent high or low refractive index materials, respectively. The refractive indices and absorption coefficients of cesium iodide, potassium bromide, sodium chloride, polytetrafluoroethylene (PTFE, Teflon), and silicon have been measured in the frequency range between 1.4 and 4.7 THz. The parameters of the Lorentz oscillator functions describing the phonon polariton dispersions of CsI and KBr have been determined.
authors.affiliation: Nonlinear Optics Laboratory, Institute of Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland. fabian.brunner@phys.ethz.ch
authors.forename: Fabian D J
authors.initials: FD
authors.lastname: Brunner
authors.forename: Arno
authors.initials: A
authors.lastname: Schneider
authors.forename: Peter
authors.initials: P
authors.lastname: Günter
mesh_terms: D001965:Bromides / Q000737:chemistry; D002586:Cesium / Q000737:chemistry; D004867:Equipment Design; D007454:Iodides / Q000737:chemistry; D055095:Optics and Photonics / Q000379:methods; D017680:Potassium Compounds / Q000737:chemistry; D012031:Refractometry; D012965:Sodium Chloride / Q000737:chemistry; D055053:Terahertz Radiation; D055068:Terahertz Spectroscopy / Q000295:instrumentation* / Q000379:methods; D013997:Time Factors
chemical_list: D001965:Bromides; D007454:Iodides; D017680:Potassium Compounds; D002586:Cesium; D012965:Sodium Chloride; C039004:potassium bromide; C040050:cesium iodide