THz near-field imaging and micro-spectroscopy

The THz frequency range has proven to be a very interesting frequency range for imaging and spectroscopy. The smallest spatial feature that can theoretically be resolved is limited by diffraction to values of about half of a wavelength, which corresponds to 150 μm for a frequency of 1 THz. To overcome this diffraction limit, terahertz near-field techniques have been developed. This talk describes techniques to overcome the diffraction limit in the THz frequency range. These techniques have been used for micro-spectroscopy and for imaging of the EM field in the neighbourhood of small antenna-like structures.