Skip to content
Skip to navigation menu

Physics Seminar

THz time-domain spectroscopy for science & technology

Speaker: Dr Miguel Navarro-Cia (University of Birmingham)
Date: Wednesday 6 November 2019
Time: 15:00
Venue: N/3.28

Despite the fact that most of the radiation emitted in the universe since the Big Bang is in the THz range, readily available THz sources did not emerge until the end of the 20th century. Also, the detection of THz waves was proven to be very challenging. Altogether slowed down the adoption of THz waves (and technology), making this spectral window sandwiched between the optical and microwave regimes (ca. 0.3 – 3 THz; wavelength range between 1 mm and 0.1 mm) relatively unexplored. A great deal of effort is now carried out to develop such spectrum as it holds promise for next generation of wireless communication, medical diagnosis, security applications (chemical fingerprinting and standoff screening) and industrial control processes. The potential of THz in these realms arises from the ability of THz radiation to provide more bandwidth than microwaves/millimetre-waves and to pass through many optically opaque materials (e.g., clothing, paper, etc.), as well as the fact that specific rotations, vibrations or librations of molecules and molecular aggregates occur in this frequency range. In addition, THz radiation is non-ionizing and safe, unlike X-rays. Terahertz time-domain spectroscopy has emerged as a main spectroscopic modality to fill this so-called THz-gap and this seminar will showcase the use of the technique for two applications: (1) development of flexible low-loss low-dispersion waveguides ('cables'); (2) understanding of the extraordinary transmission phenomenon.