Terahertz near-field microspectroscopy

Using near-field, terahertz time-domain spectroscopy (THz-TDS), we investigate how the addition of a dielectric material into a subwavelength-diameter, cylindrical waveguide affects its transmission properties. The THz electric near-field is imaged with deep subwavelength resolution as it emerges from filled and unfilled waveguides....

Measurement and calculation of the near field of a terahertz apertureless scanning optical microscope

We present measurements and calculations of the terahertz (THz) electric field measured in the near field of a metal tip used in THz apertureless near-field optical microscopy (THz-ANSOM). An analytical model in which we treat the metal tip as a linear wire antenna allows us to predict almost all of the features observed in the measurements,...

Antenna effects in terahertz apertureless near-field optical microscopy

We have performed measurements on terahertz (THz) apertureless near-field microscopy that show that the temporal shape of the observed near-field signals is approximately proportional to the time-integral of the incident field. Associated with this signal change is a bandwidth reduction by approximately a factor of 3 which is observed using both...