Electro-optic probe for electric field & temperature measurement

Category: Metrology, dosimetry


Electro-optic probe for electric field & temperature measurement




This project aims to study and design ultra-sensitive and compact electro-optic probes applied to dosimetry in biological material (in vivo and in vitro). The probe allows to record both relative temperature and electrical field. In parallel a new approach to measure 2 components of the electric field within the same electro-optic probe will be developed.




IMEP-LAHC   UMR n° 5130 CNRS / Grenoble INP



XLIM   UMR n° 6172 CNRS / University of Limoges




Lionel Duvillaret       CNRS – Laboratory IMEP-LAHC

[email protected]



18 months





1) Introduction

• A new kind of metrology should be designed to enhance Specific Absorption Rate measurement in order to detect signals emitted by WIFI-WIMAX and RFID. Detection of peak electrical field at high frequency -typically 5GHz- is needed.

• IMEP-LAHC laboratory designs a new type of electro-optic probes allowing a simulta-neous measurement of both relative temperature and peak electrical field, even if the sensitivity remains poor.

• The first part of the project addresses the enhancement of the sensitivity by one order of magnitude and correlatively a reduction of the probe size.

• The second part is dedicated to set-up a new optical processing system allowing the simultaneous measurement of 2 electric field components with a unique electro-optic probe and a unique laser probe beam.


2) State of the art

• Current temperature sensor based on fiber optic can not record complex waveform such as the one emitted in digital WIFI systems. Electrical probes are invasive and deliver a signal proportional to the square of the electric field.

• Electro-optic probes show a medium sensitivity. However they are compact, non in-vasive, and deliver a signal directly proportional to the electric field magnitude. IMEP-LAHC laboratory have designed a novel probe that is able to measure also the relative temperature.

• The project addresses sensitivity and compactness enhancement of electro-optic probes for frequency bandwidths lower than 6 GHz.


3) Scientific methodology

• Single axis probe: The study aims to get a better match between permittivities of the ambient medium and the electro-optic probe in order to lead to an enhancement of sensitivity and a reduction of its invasiveness.

• Two-axis probe: Design and testing of a novel approach to process optical polarization in order to recover simultaneously 2 components of the electric field magnitude.


4) Partnership, skills

• Partner 1: IMEP-LAHC is a laboratory with a strong expertise concerning broad band electro-optic probes to measure both temperature and electric field magnitude for de-fense applications.

• Partner 2: XLIM is an expert laboratory in studying impact of electromagnetic wave on biological in vivo material. XLIM will be the end-used committed in specifications, and electro-optic probe evaluation. XLIM will benchmark the electro-optic probe developed in this project with numerical approach and common optical probes.


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