A New Processing Technology and Detection Method for Isosceles Prism

The optical parallelism is an important indicators of isosceles prism. However, it cannot be directly measured in the processing process, and it is measured when the small surface is coated with silver film, which results in low processing rate. By analyzing the principles of the first optical parallelism and the second optical parallelism, this paper provides a new processing and detection method for isosceles prism. The good verticality between the three working face for isosceles prism and a side face can ensure the second optical parallelism. The small difference of 67.5 degrees can ensure the first optical parallelism. By changing the position of the incident light when testing, the number of reflections can be reduced from seven to three. The reflection principle deduces the formula: theta(II(7))=2.4 theta(II(3)), which to improve the machining accuracy and avoid the surface imperfections in detection. By using this process, precision and productivity can be effectively improved, the complexity of the process is reduced, and the qualification of isosceles prism has been improved.