Research on multiple-beam interference of pointolite and measurement of minute wedge angle

The intensity distribution of pointolite interference fringes and its characters are discussed by the theory of interference on the condition of glass plate thickness being non-uniform. A novel method of measuring wedge angle of plate is deduced and improved by selecting appropriate reflectivity (R). So, the glass plate with appropriate reflectivity should be adopted to improve the measurement precision for R has a much effect on fringes. The experiments and analysis show it is suitable that R is less than 0.5. By using the equations deduced, the wedge angle was measured and its value is 3.7 ÿ 10⿿4.