Single-optical-waveguide Electric-field Sensor Using Pockels Film Crystal Estimation Using Simultaneous Measurement of Many Spectra Emitted from Electrical Discharge.

有效地利用光波导技术制作了较小的Pockels器件电场传感器。研制了空间分辨率为微米级的Pockels器件光波导电场传感器，提出了一种新型的单光波导电场传感器，并通过对Pockels晶体上的光波导进行了优化设计，最终实现了该传感器。主要结果如下：1)当光束在z切LiNbO_3晶体中沿x轴传输时，使用该晶体的传感器的输出强烈依赖于环境温度。2)为了改善前面提到的缺点，新选择了一种在y切LiNbO_3晶体中沿z轴传输光束的方法。3)通过控制传感器上光路的长度，可以很容易地调整决定传感器灵敏度的光直流偏置工作点。4)试验场传感器由宽7微米、深3微米、长4.39毫米的普克尔斯晶体、波长1.31微米的激光二极管、薄膜偏振器、光纤和光电探测器组成。5)为了评估传感器的性能，对传感器施加交流电压和脉冲电压。实验证实，在雷电冲击范围内具有良好的线性度和较高的响应度。

Optical waveguide technique is effectively utilized to make a smaller Pockels device electric field sensor. Optical waveguide electric field sensors using Pockels device which are expected to have spatial resolution of micrometers are developed.In this study, a new electric field sensor using a uni-optical-waveguide is proposed and is finally realized by means of an optimum design of a waveguide on a Pockels crystal. The main results are as follows.1)When a light beam is propagated along a x-axis in a z-cut LiNbO_3 crystal,an output of the sensor using the crystal strongly depends on ambient temperature.2)In order to improve the disadvantage mentioned at the previous item, a method of propagating a light beam along z-axis in a y-cut LiNbO_3 crystal is newly chosen. It is experimentally confirmed that the new method is useful for increasing the stability of the sensor performance.3)It is found that the working point of optical dc bias which determines the sensitivity of the sensor can be easily adjusted by controlling the length of an optical path on the sensor.4)The field sensor on a trial basis consists of a Pockels crystal having optical waveguide of 7 mum in width, 3mum in depth and 4.39mm in length, a laser diode of 1.31mum in wavelength, a membrane polarizer,an optical fiber, and a photo-detector.5)Ac and impulse voltages are applied to the sensor in order to estimate the performance of it. A good linearity and a good responsibility up to a high frequency in a lightning impulse region is confirmed experimentally.