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Fiber optic electric field sensors are ideal for characterizing the electric field in many different systems. Unfortunately, many of these systems produce one or more noise types, like vibrational noise which contribute to a harsh sensing environment on the fiber optic sensor. When fiber optic sensors are placed in a harsh vibration environment, multiple noise types can overwhelm the measurements. This work shows how to simultaneously eliminate three different noise types in a fiber optic sensor induced by a harsh vibration environment. Specifically, nonlocalized vibration-induced interferometric noise is up converted to higher frequency bands by single-tone phase modulation. Then, localized vibrational noise, and radio frequency noise are all eliminated using a push–pull slab coupled optical sensor configuration to allow for an optical measurement of an electric field in a harsh environment.

This work introduces a passive dipole antenna integrated into the packaging of a slab-coupled optical sensor to enhance the directional sensitivity of electro-optic electric field measurements parallel to the fiber axis. Using the passive integrated dipole antenna described in this work, a sensor that can typically only sense fields transverse to the fiber direction is able to sense a 1.25 kV/m field along the fiber direction with a gain of 17.5. This is verified through simulation and experiment.

One of the most common methods used to measure high voltage is using a voltage divider. While this method is fairly reliable for most low frequency high voltage measurements, the voltage divider encounters difficulty when measuring higher frequency voltage signals. In these instances, the signal measured by the voltage divider becomes susceptible to distortion and inaccuracy. One solution to measuring voltages where a voltage divider would not suffice is using an electrode structure in conjunction with a fiber-based electric field sensor. A high voltage generator was constructed utilizing automotive ignition coils and was used in a capacitor-charging circuit. The voltage on the capacitor was measured using a common resistive voltage divider as well as with a fiber-based electric field sensor. Where a resistor divider was not reliable in characterizing the system, the optical sensor was successful in measuring the charge and discharge voltages of the capacitor circuit.

Electric arcs are a form of electric discharge through a non-conductive media caused by a high electric potential between two points. The timing of this discharge serves as an important parameter in high pulse power applications and a short discharge time is often desirable. We put together a circuit which operates on the principle of inducing a high voltage pulse on an ignition coil controlled by a MOSFET. Slab coupled optical sensor (SCOS) technology was used to characterize arc dynamics such as the discharge time, charge time, slope of the discharge, and effects of changing spark gap distance. In triggering the spark gap, we were able to characterize the discharge of pulses with times between 100 ms and 170 ns.

We describe the application of SCOS technology in non-intrusive, directional and spatially localized measurements of high electric fields. When measuring electric fields above a certain threshold, SCOS measurement sensitivity starts varying to a great extent and the linear approximation that assumes sensitivity to be constant breaks down. This means that a comprehensive nonlinear calibration method is required for accurate calibration of both low and high electric fields, while linear calibration can only be accurately applied for low fields. Nonlinear calibration method relies on the knowledge of the variability of sensitivity, while linear calibration relies on approximation of sensitivity with a constant value, which breaks down for high fields. We analyze and compare the two calibration methods by applying them to a same set of measurements. We measure electric field pulses with magnitudes from 1 MV/m to 8.2 MV/m, with sub-300 ns rise time and fall-off time constant of 60 μs. We show that the nonlinear calibration very accurately predicts all measured fields, both high and low, while the linear calibration becomes increasingly inaccurate for fields above 1 MV/m.

The push-pull slab-coupled optical sensor measures a localized single electric field component with the advantage of reducing adverse strain effects for sensing in harsh vibrating environments. Its miniature size makes it ideal for compact environments.

Voltage in a coaxial cable is measured by an electric-field optical fiber sensor exploiting the proportionality of voltage and electric field in a fixed structure. The sensor is inserted in a hole drilled through the dielectric of the RG-218 coaxial cable and sealed with epoxy to displace all air and prevent the adverse effects of charge buildup during high-voltage measurements. It is shown that the presence of the sensor in the coaxial cable does not significantly increase electrical reflections in the cable. A slab-coupled optical fiber sensor (SCOS) is used for its compact size and dielectric make. The dynamic range of 50 dB is shown experimentally with detection of signals as low as 1 V and up to 157 kV. A low corner of 0.3 Hz is demonstrated and the SCOS is shown to be able to measure 90 ns rise time.

A fiber-optic electric field sensor was developed to measure electric field up to 18 MV/m. The sensor uses resonant coupling between an optical fiber and a nonlinear electro-optical crystal. The sensing system uses high dielectric strength materials to eliminate dielectric breakdown. A postprocessing nonlinear calibration method is developed that maps voltage change to wavelength shift and then converts the wavelength shift to electric field using the transmission spectrum. The nonlinear calibration method is compared against the linear method with electric field pulses having magnitudes from 1.5 to 18 MV/m.