Experimental evaluation of spatial resolution for optical electric field sensor with dipole element

This paper presents a method for evaluating the spatial resolution of an optical electric field sensor with a dipole element by measurement. The electromagnetic wave radiated from a standard horn antenna was applied perpendicularly to a flat metal surface, and the electric field distribution of the generated standing wave was measured while moving the optical electric field sensor with a step width smaller than the element length. It evaluated by calculating the theoretical value of ideal dipole element length dependence by 0.1mm step. As a result, it was found that a spatial resolution equivalent to the element length can be expected with a deviation within 2.15 dB when the element length is 1 cm and the frequency is 2.5 GHz.

I. Introduction

An electric field sensor having a high spatial resolution of measuring a change in electric field strength depending on a position with high accuracy is required for evaluating electric fields in the vicinity of a wireless device or an electronic device and evaluating characteristics of an EMC test facility [1].