Abstract

Rapidly growing applications of terahertz imaging technique bring new requirements for improved resolution of such systems [1]. Combination of the THz imaging and apertureless scanning near-field microscopy (s-SNOM) allows obtaining the system resolution much beyond the classical Rayleigh limits, e.g., about 150 nm for the 2 THz (150 µm wavelength) radiation [2]. The specularly reflected signal from a metallic probe tip brought to a sub-wavelength proximity of the sample (Fig. 1 a) is detected in the far-field zone. Experimental data are not explained by the Mie scattering theory traditionally used to interpret the optical data obtained with s-SNOMs. However, a simple circuit model based on antenna theory was found to agree with the THz scattering measurements [2,3].

© 2009 IEEE