Friday 11 Febuary; Leiden, Paul Planken "Terahertz near-field imaging and spectroscopy"



Joan van der Waals Colloquium

De Sitterzaal/ Oortgebouw

16.00 - 17.00hours (drinks afterwards)


Techniques developed for the THz frequency range are surprisingly powerful tools for measuring the near-electromagnetic field of sub-wavelength sized structures. In this talk, after giving a short introduction of terahertz time-domain spectroscopy, I will show measurements of the THz near-field of a few sub-wavelength sized structures and demonstrate how these near-field techniques can also be used to measure THz resonances of crystals having sub-wavelength dimensions. In addition, I will show results on the unexpected ability of thin (tens to hundreds of nanometer thickness) layers of large-bandgap materials to generate THz radiation when
illuminated with femtosecond laser pulses.