Precision measurement of microscopic module through dual-frequency laser interferometer

In order to accurately measure the high-precision microscopic module of optic fiber array , a method combined a dual-frequency laser interferometer with a micro-vision system was adopted. The characterized scale was extracted and located precisely from the micro-vision image by way of skeletonization, erosion algorithm and the centroid method. The spaces between 8 scales were repetitively measured, with the maximum standard deviation being no more than 0.07 m. These 8 scales were further measured through the combination method, with the maximum standard deviation being no more than 0.04 m. The configuration and principle of the measurement system were described. Accuracy analysis indicates that the limit error of the method is less than 0.10 m.