| Abstrakt: |
A lithium niobite [LiNbO3 (LN)] optical intense electric field sensor with linear operating point set by twisting the polarization-maintaining fiber (PMF) was designed, developed, and experimentally demonstrated. Experimental results reveal that the coupling efficiency of the sensor is improved by 25.3% compared with traditional optical electric field sensor using the 1/4 wave plate. Besides, for the measurement of intense power-frequency electric field, the linear measurement range of the sensor is 12.8–524 kV/m, and the linear correlation coefficient is 0.9989. For the measurement of lightning electromagnetic pulse (LEMP), it was found that the sensor detected waveform was superimposed with a resonant noise of 720 and 980 kHz. Theoretical analysis yielded a relationship between the direction of the applied electric field, crystal size, and resonant frequency. The resonance energy was eventually dispersed by using a trapezoidal LN crystal, and it was found that the resonant noise has been suppressed to below −30 dB. |
