THz near-field imaging based on a tapered parallel-plates

A broad-band low-loss no-cut-off THz near-field imaging technique has been demonstrated experimentally. This technique works in reflection mode using a tapered parallel-plate waveguide (PPWG) as a probe. Images reconstructed by the filtered back-projection algorithm are able to resolve features of size ~100 μm, using radiation with an average wavelength of 1.5 mm.