The consequences of diffractively spreading beams in ultrafast THz spectroscopy

Bowen, J. W., Walker, G. C., Hadjiloucas, S. ORCID: https://orcid.org/0000-0003-2380-6114 and Berry, E. (2004) The consequences of diffractively spreading beams in ultrafast THz spectroscopy. In: Thumm, M. and Wiesbeck, W. (eds.) Conference Digest of the 2004 Joint 29th International Conference on Infrared and Millimeter Waves and 12th International Conference on Terahertz Electronics. IEEE, New York, pp. 551-552. ISBN 0780384903

Abstract/Summary

There are established methods for calculating optical constants from measurements using a broadband terahertz (THz) source. Applications to ultrafast THz spectroscopy have adopted the key assumption that the THz beam is treated as a normal incidence plane-wave. We show that this assumption results in a frequency-dependent systematic error, which is compounded by distortion of the beam on introduction of the sample.