Fig. 1. Schematic diagram of heterodyne interferometer

Fig. 2. Schematic diagram of heterodyne interferometer with phase compensator^[23]

Fig. 3. Schematic diagram of dual-phase detection method for nonlinear error of heterodyne laser interferometer^[27]

Fig. 4. Schematic diagram of Wu-type interferometer^[29]

Fig. 5. Schematic diagram of Lawell-type interferometer^[30]

Fig. 6. Schematic diagram of Joo-type interferometer^[31]

Fig. 7. Schematic diagram of Joo-type plane mirror four-division interferometer^[33]

Fig. 8. Schematic diagram of Joo-type interferometer using optical fiber^[34]

Fig. 9. Schematic diagram of heterodyne interferometer with integrated components^[37]

Fig. 10. Schematic diagram of heterodyne interferometer with balanced planar mirror^[36]

Fig. 11. Schematic diagram of Weichert-type interferometer^[38]

Fig. 12. Schematic diagram of dual-frequency green light interferometer^[40]

Fig. 13. Schematic diagram of interferometer with highly symmetric optical structure^[35]

Fig. 14. Schematic diagram of dual-homodyne interferometer ^[42]

Fig. 15. Nonlinear error measurement system^[52,56]

Fig. 16. Data graph of nonlinear error measurement

Fig. 17. Schematic diagram of Fabry-Perot interferometer system^[57]