A Novel Space Charge Optical Measurement Method in Electronic Device Insulation System

To facilitate the accurate evaluation of insulation in electronic devices, it is imperative to expedite the advancement of innovative technologies in space charge measurement that possess superior temporal–spatial resolution and rapid reaction capabilities. This study presents a proposed approach for charge measurement that leverages the electro-optical effect and the optoelectronics principle. A femtosecond laser excitation and ellipsometry detection method is innovatively introduced. The MHz excitation frequency and pulse-width in ps levels guarantee an excellent spatial resolution and measurement speed. Meanwhile, the bandwidth limit and safety isolation problems associated with traditional electrical detection components are addressed. The experimental results show that the rapid tracking of charge signals with repetition rates in the kHz range and pulse-width in the nanosecond range can be accomplished by the constructed measurement system. In addition, simulations of the sensor response under picosecond electric fields demonstrate the feasibility for achieving nanoscale spatial resolution. This study contributes to the development of the space charge measurement technology with high temporal-spatial resolution.