光干涉法测量压电陶瓷压电特性

Piezoelectric Characteristic Measurement Using Laser Interference Method

用待测压电陶瓷来控制迈克尔逊干涉仪其中一臂上的全反镜的位置,分析得出由于光学干涉作用,迈克尔逊干涉仪输出的光功率与压电陶瓷伸长量一一对应。又因为带有本征层的光电探测器输入光功率与输出电压成正比,所以再利用双踪数字示波器就可巧妙测量压电陶瓷的压电特性。从数字示波器记录的干涉图可直观地发现在不同电压下压电陶瓷伸长半个光波长所需要增加的电压。从数字示波器记录的数据可得压电陶瓷所加电压与其伸长量的对应关系。

The position of one reflected mirror of Michelson interferometer can be controlled by piezoelectric ceramics.Through analysis of the optical interference,a one-to-one correspondence is obtained between the output optical power of the Michelson interferometer and the elongation of piezoelectric element.Since the input optical power of the PIN photodetector is proportional to the output voltage,the piezoelectricity of the piezoelectric ceramic can be measured by using the dual trace digital oscilloscope.It is can be found that the desired increments of the voltage to elongate half optical wave length of piezoelectric ceramic under different voltages through the interferogram of the digital oscilloscope.The relation curve between the displacement and the voltage of piezoelectric element is obtained from the recorded data of the digital oscilloscope.