Pierre Jarrige, Gwenaël Gaborit, Lionel Duvillaret, Sophie Kohler, Nicolas Ticaud, Delia Arnaud-Cormos, Philippe Lévèque
Here, we present the suitability of an electro-optic probe for performing simultaneous electric-field and temperature measurements in the case of bioelectromagnetic experiments such as specific absorption rate (SAR) assessments, or the characterization of in-situ nanosecond pulsed electric fields (nsPEF). In the frequency domain, the millimeter-sized probe, immersed in a water solution, reached a sensitivity of 170mVm−¹ Hz ¹/² , and presented a dynamic range exceeding 70 dB. Furthermore, temperature measurements led to a resolution of 22 mK. These abilities were used to perform dual SAR assessments by simultaneous electric-field and temperature measurements. Thanks to its ultra-wide bandwidth, the electro-optic probe is particularly suited for high transient electric-field measurements in the time domain. Pulses with different shapes and intensities were visualized and investigated.
Radio frequencies constitute a part of the electromagnetic (EM) spectrum extensively exploited for many domestic, industrial, and medical applications. Their massive use has led to new questions about the potential effects on health of this non-ionizing radiation. Together with the knowledge of the different interaction mechanisms and the physical quantities involved, quantifying the effects resulting from exposure to electromagnetic radiation is thus a major issue. For this purpose, the SAR is the reference dosimetric parameter used to quantify the energy absorbed by tissues. It can be assessed in two ways: by measuring the electric field in the exposed biological medium, or by measuring the temperature rise resulting from the RF exposure. Consequently, there are two types of instrumentation for assessing SAR: temperature sensors and electric-field probes. The first type is based on the use of thermistors, or consists of the use of a thermo-optical effect [1-3]. Electric-field probes can be divided into two major families: metal-based probes and electro-optic (EO) probes…
The Radio Science Bulletin No 342 (September 2012)