Millimeter waves offer a good combination of resolution and penetration for the development of active mm wave imaging systems for non-destructive testing applications. Our research activities focus on various imaging modalities such as physical aperture imaging, conventional and transient radar imaging, synthetic aperture imaging, near-field imaging and compressed sensing and imaging.

The research activities encompass the design of imaging system architectures, image forming optics, fast scanning techniques, multi-parameter (frequency, angle, polarization, phase) illumination techniques.

Conventional optical imaging systems in the mm-wave and THz range (0.1 < λ < 10 mm) cannot resolve microscopic details as the resolution in the far field is limited by diffraction (Rayleigh criterion). Super resolution is however feasible by detection of scattered evanescent waves, which are only detectable in the direct neighbourhood of the object by putting a field scattering microprobe. We investigate the potential of a scanning scattering type near-field mm-wave imaging method based on the interaction between a very sharp probe tip and the object whereby the resolution is no longer determined by the wavelength but by the sharpness of the tip.