Frequency characteristics calibration of optical electric integrated sensor for intensive electric field

Optical electric integrated electric field sensor (OEFS) has the advantages of small scale, large frequency range, high electric field measurement capability, and et al. It's an effective experimental method for the research of high voltage technology. The frequency characteristics of OEFS have to be calibrated before using OEFS in the measurement of time domain waveform of electric field. Normal calibration method can not satisfy the requirement of this kind of electric field sensor, because OEFS is used to measure intensive electric field and has not enough sensitivity to response the low strength electric field from the normal calibration device. The demand of the calibration for the electric field sensor used in high voltage technology was analyzed in this paper, and so was the calibration demand of the OEFS. Frequency characteristics calibration scheme was researched. Different calibration types, frequency domain calibration and time domain calibration, were compared and latter was used in this paper. The three kinds of calibration methods recommended by IEEE standard were introduced, and the method using calculated field strength was chosen. Nuclear electromagnetic pulse was used as calibration waveform and parallel strip transmission line was used as calibration device. Frequency characteristics calibration experiment was carried out in a bounded electromagnetic pulse simulator, and time domain waveforms from the voltage divider and the OEFS were compared. In can be concluded from the experiment results that the rise time of OEFS is less than 1.12 ns, and the 3 dB upper limit frequency is higher than 313 MHz. OEFS can be used in measurements of the high frequency signals, such as the radiation electric field of VFTO, in high voltage technology.