Characterization of electromagnetic fields of radiating systems by thermo-fluorescence

Characterization of the electromagnetic field emitted by various sources (antenna, radar) is an important issue, either for civil or defense applications. The measurement of the electromagnetic field may be performed by a local probe, the infrared thermography imaging being an alternative way. The latter method, called EMIR [1] (ElectroMagnetic InfraRed) has been used for years at ONERA where it had been developed. We have recently successfully implemented this technique in the domain of visible light, named as EMVI [2] (ElectroMagnetic Visible Imaging). As in EMIR, a thin film (sensitive to either electric field or magnetic field) is heated by the emitted field. But here the film is coated with a polymer doped with fluorescent molecules. As the fluorescent emission depends on the temperature of the film, we achieve a novel thermofluorescent sensor. The results presented here illustrate that new method: both magnetic and electric field imaging of two different radiating systems.