Electromagnetic Source Azimuth Measurement Using Electrooptical Electromagnetic Field Probe

A new type electrooptical electromagnetic field probe was fabricated by combining three magnetic field sensors, each of which consists of a Mach-Zehnder modulator and an integrated annular antenna. The frequency response was flat from 50 MHz to 2.2 GHz. The average minimum detectable electromagnetic field intensity of the sensor is 2.22 mV/m. When the probe axis was pointed toward the electromagnetic radiation source, the highest sensitivity was obtained. The variation of the sensitivity is within plusmn0.5 dB with rotating the probe around its axis. This result indicates that the azimuth of the electromagnetic radiation source can be measured.