Bernd M. Fischer

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An Australian research group has investigated a number of terahertz application areas including liquid Tray spectroscopy, bioaffinity sensing, image rendering, tomography, microwire Tray transmission, and detection through plastic layers. ABSTRACT | Tray wavelengths are long enough to pass through dry, nonpolar objects opaque at visible wavelengths, but(More)
The thickness of a sample material for a transmission-mode terahertz time-domain spectroscopy (THz-TDS) measurement is the subject of interest in this paper. A sample that is too thick or too thin can raise the problem of measurement uncertainty. Although greater thickness allows the terahertz radiation--or T-rays--to interact more with bulk material, the(More)
Measurements of optical constants at terahertz—or T-ray—frequencies have been performed extensively using terahertz time-domain spectroscopy (THz-TDS). Spectrometers, together with physical models explaining the interaction between a sample and Tray radiation, are progressively being developed. Nevertheless, measurement errors in the optical constants, so(More)
The paper examines several types of anomalously dispersive media that support the argument for superluminal propagation which is the propagation of electromagnetic waves at group velocities exceeding the speed of light. ABSTRACT | This paper reviews earlier studies on superluminal wave propagation in anomalously dispersive media that have been carried out(More)
We propose a novel class of optical fiber with a porous transverse cross-section that is created by arranging sub-wavelength air-holes within the core of the fiber. These fibers can offer a combination of low transmission loss and high mode confinement in the THz regime by exploiting the enhancement of the guided mode field that occurs within these(More)
Terahertz spectroscopy has emerged as an important tool for identification and classification of materials, which exhibit absorption features at specific and distinct frequency bins in the THz spectrum. The scattering of terahertz radiation from granular substances can significantly distort the spectral fingerprint of the material under study. In this paper(More)
— One source of disturbance in a pulsed Tray signal is attributed to ambient water vapor. Water molecules in the gas phase selectively absorb Trays at discrete frequencies corresponding to their molecular rotational transitions. This results in prominent resonances spread over the Tray spectrum, and in the time domain the Tray signal is observed as(More)
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