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

利用光波导技术有效地制作了体积更小的波克尔斯电场传感器。利用Pockels器件研制了空间分辨率可达微米级的光波导电场传感器。本文提出了一种基于单光波导的新型电场传感器，并通过对波克尔斯晶体波导的优化设计实现了该传感器。主要结果如下：1)当光束在z切割LiNbO_3晶体中沿x轴传播时，使用该晶体的传感器的输出强烈依赖于环境温度。2)为了改善上一项所提到的缺点，本文选择了一种在y型切割LiNbO_3晶体中沿z轴传播光束的方法。实验证明，该方法有助于提高传感器性能的稳定性。3)通过控制传感器上光路的长度，可以很容易地调节决定传感器灵敏度的光直流偏置工作点。4)试验性场传感器由宽7 μ m、深3 μ m、长4.39mm的波克尔斯晶体、波长1.31 μ m的激光二极管、膜偏振器、光纤和光电探测器组成。5)对传感器施加交流电压和冲击电压，以估计其性能。实验证实了该电路在雷击区域内具有良好的线性度和良好的高频责任。

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.