Study on the testing device of axis parallelism

Refer to the dynamic optics theory, there is no image deflection in the rotation process of right-angle-roof prism and rhombic prism around any axis in space. That is to say, after reflection, the output optical axis from the prism is parallel to the direction of the initial optical axis. The optical character of right-angle-roof prism and rhombic prism is applied in this paper. A new testing method of multi-axis parallelism with chain of combined multi-right-angle-roof prisms or multi-rhombic prisms is proposed. And the testing error is analyzed in detail.