Photonic electromagnetic field sensor developments

The paper presents the development of the photonic sensors for electromagnetic field (EMF) measurements. The first applications were limited to the telemetry only. The basic advantage of photonic sensors is the preserved spectral and phase information. Attempts to improve the sensitivity of sensors are illustrated with a Mach-Zehnder interferometer and internal FM modulation of a laser with heterodyne detection. A new concept of the sensor with the use of the Fabry-Perot filter as a wideband frequency discriminator is introduced. Widebandedness limitations due to elasto-optic phenomena in electro-optic crystals and pattern synthesis are mentioned.