Comparison of THz and near-IR scattering effects from air-solid interfaces

Scattering attenuation from roughened glass surfaces is studied experimentally in the near-IR and THz regions. The IR attenuation is substantial — up to 3-dB per interface in the 1.55-micron region — on samples having ∼1-μm RMS surface roughness. The same samples show negligible scattering attenuation in the THz region. This is important for biomedical applications, such as skin-burn and corneal sensing, for which THz and IR technologies are competing for acceptance.