Integrated electrooptical electromagnetic field sensor with mach-zehnder waveguide modulator and annular antenna

A small electromagnetic field sensor in the frequency range from 50 MHz to 2 GHz was developed that consisted of a Mach-Zehnder waveguide modulator and a micro annular antenna, which was directly integrated with the traveling-wave electrode of the Mach-Zehnder waveguide modulator on the same LiNbO₃ substrate. The size of the sensor is 45 mm × 10 mm × 1 mm, demonstrating that the new kind of design successfully miniaturized the sensor size. The average minimum detectable electromagnetic field intensity of the sensor is 3.9 mV/m. The result indicates that the new kind of sensor is of potential interest for future application.