Electromagnetic fields of a current loop above a chiral half space

Abstract

The electromagnetic fields due to an electrically small current loop located above a chiral half space are derived in integral forms that can be evaluated numerically. It is shown that for a loop whose axis is perpendicular to the air/chiral interface, the fields have both TE and TM components. The latter is a direct result of chirality. Therefore, the chirality parameter can be inferred from the ratio of TM to TE field components. Approximate, but sufficiently accurate closed forms are derived for the fields in the near zone or under the quasistatic condition k_or < 1. A simple image theory is developed to approximate the TE and TM fields in the air region when k_or > 1. It is shown that the image theory is sufficiently accurate except when used to evaluate the field very near to the air/chiral interface.