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)
Using conventional materials, the resolution of focusing and imaging devices is limited by diffraction to about half the wavelength of light, as high spatial frequencies do not propagate in isotropic materials. Wire array metamaterials, because of their extreme anisotropy, can beat this limit; however, focusing with these has only been demonstrated up to(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)
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 present the hygroscopicity of polymer and copolymer materials in the low terahertz (THz) frequency range using a linear absorption model. We identify COC 6013 and COC 5013 as optimal THz window materials, possessing both low hygroscopicity and high transmission in the THz regime. The correct choice of window material is of significance for transmission(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)