A 3D Mach-Zehnder Time-Domain EO Sensor for the EMP Measurement

A three-dimensional (3D) Mach-Zehnder electro-optical sensor for the measurement of electromagnetic pulse (EMP) is designed and fabricated. The Mach-Zehnder modulation structure based on LiNbO
3
is used for the design of 3D sensor. Based on a tapered dipole patch antenna model, the electrode and antenna integrated structure is designed. The characteristic of the antennas are simulated and the structure parameters are determined based on CST. The size of the main structure of the fabricated 3D sensor is less than 10 cm × 6 cm × 6 cm. The test results show that the rise time of the sensor is less than 0.6 ns combined with a 1 GHz photo detector, and the measurement range is ±3 kV/m~ ±100 kV/m. The developed 3D sensor can response well to the nanosecond risetime EMP.