Fig. 1. Structure diagram of self-calibration roll angle measurement based on polarization splitting

Fig. 2. Measuring principle of roll angle based on dual beam. (a) Optical configuration; (b) relationship between roll angle and light spot positions of QD1 and QD2

Fig. 3. Roll error measurement caused by non-parallelism. (a) Optical configuration; (b) position of light spot on QD1 and QD2

Fig. 4. Light path of roll angle based on dual beam

Fig. 5. Principle of roll angle measurement based on polarization splitting. (a) Optical configuration; (b) relationship between polarization direction and PBS attitude

Fig. 6. Incident angle deviates from the Brewster angle

Fig. 7. Flow chart of the self-calibration roll angle measurement

Fig. 8. Mechanical structure of measuring device

Fig. 9. Ground noise test experiments. (a) Shield; (b) ground noise test of QD; (c) ground noise test of PD

Fig. 10. Vertical straightness calibration experiment. (a) Experimental device; (b) performance test

Fig. 11. Repeatability error experiment

Fig. 12. Roll angle calibration experiment. (a) Experimental device; (b) performance test

Fig. 13. Non-parallelism measurement and calibration effect. (a) Non-parallelism measurement; (b) calibration effect