Active optical sensor for electromagnetic field measurements in time and frequency domains

We present a miniature fiber-optic magnetic field sensor that is capable of detecting the amplitude and phase of the measured field in the frequency range from 0.1–6 GHz. It is also capable of capturing the full time domain (base-band) signal information of modern communication signals. The sensor is based on a versatile optical platform to which various antenna types and amplifier stages may be connected. The millimeter size and full electrical isolation allow field measurements with minimal disturbance. The sensor has been fully characterized and calibrated in well-defined field conditions in wave-guide structures over the frequency range.