Pierre Jarrige, Nicolas Ticaud, Sophie Kohler, Rodney P. O’Connor, Lionel Duvillaret, Gwenael Gaborit, Delia Arnaud-Cormos, Member, IEEE, and Philippe Leveque, Member, IEEE
In this paper, we present radio-frequency electromagnetic field characterization of an electrooptic (EO) probe. This probe is able to simultaneously measure temperature and one component of the electric field (e-field) in a continuous wave (CW) or in a pulsed regime. For this purpose, linearity, selectivity, and sensitivity measurements are performed in air and in a cuvette filled with a water solution. The media are exposed to 1800-MHz CW electromagnetic wave through a transverse electromagnetic cell. Numerical characterization is also performed using finite difference time-domain simulations. The EO probe presents a dynamic range exceeding 70 dB. Selectivity up to 25 dB is measured, demonstrating the ability of the EO probe to measure one unique component of the e-field. The EO probe sensitivity is equal to 0.77 and to 0.18 V · m-¹ Hz−¹⁄², in the air and in the water solution, respectively. This millimeter-sized EO probe is particularly suited for the measurement of ultrawide bandwidth and high-voltage e-fields up to a few megavolts per meter.
To assess the potential effects of RF electromagnetic fields on human health, electric-field (E-field) probes and temperature probes are extensively used –. Indeed, the interaction between time-varying electromagnetic fields and biological systems such as tissues or cells can be quantified from the temperature rise or the E-field induced in the exposed medium. More precisely, the standard parameter for assessing the interaction, namely, the power absorbed by the medium, is the specific absorption rate (SAR) –. For experimental SAR assessment via E-field measurements, two types of E-field probes are basically used: metal-based probes such as diodeloaded dipole sensors and electrooptic (EO) probes , , –. Due to their fully dielectric structure and small size, EO probes are much less invasive than metal-based electromagnetic field probes…
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 61, NO. 7, JULY 2012