Fig. 1. Grating displacement measurement system

Fig. 2. Grating rotation around the x⁃axis

Fig. 3. Grating rotation around the y⁃axis

Fig. 4. Schematic diagram of the rotation of grating around the y⁃axis

Fig. 5. Grating rotation around the z⁃axis

Fig. 6. Rotation error of the mirror about the y⁃axis

Fig. 7. Schematic diagram of the rotation of mirror around the y⁃axis

Fig. 8. Displacement test error of grating rotating around the y⁃axis

Fig. 9. Displacement test error of grating rotating around the z⁃axis

Fig. 10. Displacement test error of mirror rotating around the y⁃axis

Fig. 11. Experimental optical path

Fig. 12. Comparison of theoretical and experimental data