Effects of surface roughness on reflection spectra obtained by terahertz time-domain spectroscopy.
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.
Dikmelik
Yamac
Y
Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA. yamac@jhu.edu
Spicer
James B
JB
Fitch
Michael J
MJ
Osiander
Robert
R