An Electro-Optical Technique for Measuring High Frequency Free Space Electric Fields

Abstract

Electro-optical voltage measurement techniques, based on the Kerr and Pockels effects, offer a number of advantages over conventional resistive or capacitive voltage dividers. As with all electron analog sensors, their performance is affected by EMI, ground loops, and noise pickup; and their frequency response is limited by stray capacitance and inductance associated with the divider circuits. Optical analog sensors are not susceptible to these perturbations and are often considered superior [1]. One of the most outstanding characteristics of optical analog sensors is their inherent band width; for example, the intrinsic response time of Kerr fluids is measured in picoseconds [1]. In practice, however, the cells are placed between electrodes and the associated capacitance usually limits the sensor band width to less than 1 GHz. In addition, electrodes may introduce electrical breakdown along the surface of the cell. These concerns are contributing factors to the under utilization of the electro-optic techniques in pulse power research and systems.