490 / 2022-03-17 09:47:49

Non-intrusive measurement of electric field with a high spatial-temporal resolution: electric field induced second harmonic (E-FISH)

electric field

Purpose/Aim

Electric field is one of the most important microscopic parameters in the field of high voltage (HV), insulation, and gas discharge. It is demanding to seek a non-intrusive measurement method for electric field with a high spatial-temporal resolution, which can be applied in a complex electromagnetic environment.

Experimental/Modeling methods

In this work, a laser system for electric field measurement, i.e., electric field induced second harmonic (E-FISH), which is based on the third-order non-linear interaction between laser and electric field, is built-up. Pulsed laser (ns/ps/fs) is focused to the measurement area to achieve a high spatial-temporal resolution. The intensity of second harmonic light, which is in proportion to the square of electric field strength, is collected.

Results/discussion

The spatial distribution and temporal evolution of electric field in different kinds of nanosecond pulsed discharges at atmospheric pressure are obtained. Interaction between focused laser and non-uniform electric field is analysed. The contribution of both space charges and surface charges to electric field is clarified. The propagation dynamics of pulsed gas discharge is illustrated based on electric field evolution.

Conclusions

The results in this work verify the feasibility of E-FISH method, which has the potential to be applied in HV engineering field.