Polarization-dependent measurement of the near-field distribution of a waveguide with subwavelength aperture

The understanding of the near field is essential for scanning near-field optical microscopy. We present here a simple model experiment to examine the polarization of the near field in the proximity of a subwavelength aperture. We make use of microwaves, a fast diode, and different apertures. This allows us to model a polarization-sensitive scanning near-field optical microscope by mapping the field intensity around the aperture in the near-field region.