Polarization standing wave interferometer for displacement measurement

• Main Authors: You-Xin Wang, 王佑薪
• Other Authors: Ju-Yi Lee
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/93xqr9

碩士 === 國立中央大學 === 機械工程學系 === 107 === In this study, a new type of optical interferometer is proposed: Polarization standing wave interferometer. This new interferometer integrates optical interference system, phase quadrature analysis technique, and up-and-down counting technique. It can be used for long-stroke displacement measurement with an accuracy of several nanometers. In the 21st century, industrial technique is strongly rely on precision displacement measurement. The semiconductor process technique has reached several nanometer levels. It is necessary to be supported by an interferometer to ensure the correct position during operation. In the industry, there are some ordinary commercial interferometers such as HP interferometers and grating interferometers. The advantages of them are extremely high measurement accuracy and a large measurement range. However, the configuration of them are usually bulky and expensive, and are complicated to calibrate and set up. In order to improve these problems, we have designed a polarized standing wave interferometer constructed with a single beam. The advantages are smaller built equipment space, the configuration uses fewer components, it is easy to adjust and calibrate, arranging with polarization interference technique and up and down counting technique. Above all it’s better than commercial interferometers. The principle of the system is to form a standing wave by overlapping the light transmitted to the left and right, and then scattering the standing wave light field by using a nanosphere scattering plate. By means of detecting the phase variations of the scattered light from the scattering plate with the polarization phase quadrature technique, the displacement can be determined precisely. The experimental results shows that the measurement range can reach the millimeter level. The measurement resolution reach 1 nm, the measurement sensitivity is 1.35 , and the maximum measurement speed reach 1.6 mm/s.