Electro-Optical System for EMP Measurement

An electro-optical system is described for measuring the E-field component of electromagnetic pulses (EMP) produced by an EMP-simulator. Typical rise time of these pulses is down to 10 ns, measured E-field strength from 1-500 kV/m. The measurement device consists of a He-Ne-Laser as the light source, fiber optics as the transmitter with a length of up to some hundred meters, a Pockels-cell with two polarizers as the sensor modulating the light intensity in dependence of E-field strength, and a photodiode with preamplifier and storage oscilloscope as the detector. The wide E-field range can be measured by capacitively coupling the E-field to the Pockels-cell via pairs of plane antennas with variable area. Measurements are shown of pulses produced by a laboratory simulator and a field simulator.