THz transmission near-field imaging with very high spatial resolution

Summary form only given. Scanning near-field microscopy at THz frequency regime is a developing technology and different approaches have been proposed to improve spatial resolution. Recently a sensitive near-field probe that integrates a subwavelength aperture and a photoconducting switch was demonstrated. Spatial resolution of this method is defined by the probe aperture size and limited by signal attenuation. In this study we discuss attenuation of single-cycle THz pulses for various aperture sizes (10-50 /spl mu/m). The near-field probe with the 10 gm aperture provides spatial resolution of /spl sim/10 /spl mu/m at the wavelength range from 120 to 1500 /spl mu/m. To our knowledge, it is the highest resolution achieved with THz pulses in this spectral range. Near-field images can be constructed with signal to noise ratio of /spl sim/50.