An integrated electro-optic magnetic field sensor based on reflected Mach-Zehnder interferometer

An optical magnetic field sensor using reflective Lithium niobate (LiNbO3) integrated optical waveguide Mach-Zehnder interferometer (MZI) has been proposed, designed and fabricated. The bare chip size of the sensor is microminiaturized as small as 20 × 5 × 0.5 mm3. Experiment results reveal that the sensor has wide frequency response from 10 MHz to 2 GHz with variation less than ±3.3 dB. Besides, the input/output of the sensor exhibit linear relationship as the magnetic field varied from 69.4 dBμA/m to 129.4 dBμA/m. The minimum detectable magnetic field is 65.4 dBμA/m and the dynamic range of the sensor is more than 60 dB.