铌酸锂双面金属包覆波导电压传感特性

Characteristics of LiNbO_3 waveguide voltage sensor based on symmetrical metal-cladding optical waveguide

设计了一种利用铌酸锂作为波导基片的双面金属包覆平板光波导,利用波导中超高阶导模高敏感特性制成了一种反射型光学电压传感器。入射激光束采用小角度入射,当光波导处于导模共振状态时,选择一个恰当的工作点,再通过两金属电极对该器件施加直流电压,通过检测反射光强,获得相应的电压值变化。实验测量中所用的电压范围是-800～800 V,得到的线性度值为0.995,波导反射光的反射率变化灵敏度为0.2%V^(-1),实验表明这种电压传感器具有较好的线性和灵敏度,该新型电压传感器具有结构与制作简单、调节方便和成本低廉等优点。

A new type of voltage sensor employing a symmetrical metal-cladding optical waveguide structure is proposed which utilized the sensitive property of ultrahigh-order modes of the metal-cladding optical waveguide.The voltage change can be determined by measuring the reflected light intensity when a direct voltage is applied to two electrodes to modulate the reflected light intensity through the refractive index change of LiNbO_3.The measurement range of voltage is from—800 V to 800 V with linearity of 0.995.The sensitivity coefficient of reflectivity light intensity is about 0.2%V^（-1）.The results show that the voltage sensor has good linearity and high voltage sensitivity.And it has advantages of easy operating and cheap building up in measurement.