压电陶瓷液体调相器的性能检测

Performance test of piezoelectric ceramic liquid phase modulator

光学综合孔径成像技术的关键是解决共相位问题,子孔径之间的相位失调会严重影响成像质量,工程上一般要求调相精度达到光波段λ/10。本文采用压电陶瓷制备一种液体调相器,利用干涉法和数字图像处理技术实现对调相器相位的高精度检测。通过向压电陶瓷腔注入液体来制备调相器,利用干涉仪获得压电陶瓷液体调相器在不同电压下的干涉条纹并使用CCD记录,最后对这些干涉条纹图像进行数字图像处理,得到单个像素的条纹骨架,采用条纹标记法跟踪不同电压下骨架条纹的移动情况,并计算骨架条纹的像素移动量。实验结果表明,在0~30 V的电压下,压电陶瓷液体调相器的调相范围为0~3.325π,调节精度可以达到λ/40,并且在电压区间内调相的线性度良好,满足光学综合孔径中单个子镜的相位调制精度要求。

The key of optical synthetic aperture imaging is to solve the problem of common phase.The phase imbalance between sub apertures will seriously affect the imaging quality.Generally,the phase modulation accuracy of 1/10 wavelength in optical band is required in engineering.In this paper,a liquid phase modulator was fabricated by piezoelectric ceramics.The phase of the liquid phase modulator was detected with high precision by using interference method and digital image processing technology.The phase modulator was prepared by injecting liquid into the piezoelectric ceramic cavity.The interference fringes of the piezoelectric ceramic liquid phase modulator under different voltages were obtained by using the interferom‐eter and recorded by CCD.Finally,a series of digital image processing were performed to obtain the fringe skeleton of a single pixel.The fringe marking method was used to track the movement of the skeleton fringe under different voltages.The pixel movement of skeleton stripe was calculated.The experimental results show that the phase modulation range of the piezoelectric ceramic liquid phase modulator is 0-3.325 π under 0-30 V voltage,and the adjustment accuracy can reach 1/40 wavelength.The phase modulation linearity is good in the voltage range,which meets the phase modulation accuracy requirements of single sub mirror in optical synthetic aperture.