title: Effects of surface roughness on reflection spectra obtained by terahertz time-domain spectroscopy.
abstract: We present an analytical model that shows that reflection from a rough surface causes a Gaussian frequency roll-off for the spectral magnitude of a terahertz wave and reduces the signal-to-noise ratio of terahertz time-domain spectroscopy. The parameter that determines the width of the frequency roll-off is the standard deviation of the surface height distribution. Measurements of terahertz waves reflected from copper powder samples provide experimental evidence for this effect.
authors.affiliation: Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA. yamac@jhu.edu
authors.forename: Yamac
authors.initials: Y
authors.lastname: Dikmelik
authors.forename: James B
authors.initials: JB
authors.lastname: Spicer
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Fitch
authors.forename: Robert
authors.initials: R
authors.lastname: Osiander