8 research outputs found
A novel 3D printed focusing probe in scattering-type scanning near-field millimetre & terahertz wave microscope
Super-Enhancement Focusing of Teflon Spheres
A Teflon (Polytetrafluoroethylene, PTFE) sphere can be used as a focusing
lens in the applications of imaging and sensing due to its low-loss property in
the terahertz (THz) band. In this paper, we analytically calculated field
intensities and focusing parameters for Teflon spheres at different low-loss
levels and then discovered a super-enhancement focusing effect in the spheres
with particular size parameters, which can stimulate about 4000 times stronger
field intensity than that for incident radiation as well as the great potential
of overcoming diffraction limit despite high sensitivity to the magnitude of
Teflon loss. A subsequent analysis of scattering amplitudes proved that the
strong scattering of a single order mode in the internal electric or magnetic
field is the main factor causing this phenomenon.Comment: 12 pages, 6 figure
Intelligent hyper-spectral mm-wave illumination techniques for feature extraction of hidden objects in indoor security applications: a fusion of photonics, electronics and electromagnetism
A review on thin-film sensing with terahertz waves
In the past two decades, the development and steady improvement of terahertz technology has motivated a wide range of scientific studies designed to discover and develop terahertz applications. Terahertz sensing is one such application, and its continued maturation is virtually guaranteed by the unique properties that materials exhibit in the terahertz frequency range. Thinfilm sensing is one branch of this effort that has enjoyed diverse development in the last decade. Deeply subwavelength sample thicknesses impose great difficulties to conventional terahertz spectroscopy, yet sensing those samples is essential for a large number of applications. In this article we review terahertz thin-film sensing, summarizing the motivation, challenges, and state-of-the-art approaches based predominately on terahertz time-domain spectroscopy