One-dimensional subwavelength position determination exploiting off-axis parabolic mirror

Abstract

We demonstrate a subwavelength position determination method for the terahertz region. Previously, we reported that an off-axis parabolic mirror generates a peculiar transient rotational distribution around the focus on the subwavelength scale. In the method proposed herein, the position is determined by measuring the electric field scattered by a sample placed at this rotational distribution. We perform a realistic numerical calculation and show that this method is feasible for a sample on the wavelength scale and can distinguish a displacement of the order of 0.01 wavelengths. This method can be easily implemented for micro and nanoscale measurement and processing in the terahertz region.

Incompatible case of perfect conductor approximation in vacuum nonlinear electromagnetism

“…In many cases, it is not practical to fully calculate such an interaction. In classical electromagnetism, several approximations have been established and are now widely used [32], e.g., the physical optics approximation [33] and the discrete dipole approximation [34,35]. In particular, the perfect conductor approximation [36] for a mirror surface is essential because it enables us to perform an analytic calculation and decrease the amount of numerical calculation.…”