Fig. 1. Experimental setup for power-to-phase conversion measurement of femtosecond laser synthetic wavelength method

Fig. 2. RF power of different beat notes as a function of incident optical power

Fig. 3. PPC effect of different beat notes. (a) Phase difference and (b) coefficient α as a function of the incident optical power (inset in Fig. (b) shows the coefficient α while the optical power is less than 3mW)

Fig. 4. Relationship between calculated distance by the 800 MHz fine ruler and optical power and RF power. (a) Optical power; (b) RF power; (c) LUT fitted by different orders of polynomial

Fig. 5. Experimental results. (a) Comparison of 800MHz corrected and uncorrected ranging results at a fixed position of 10mm; (b) ranging error after fitting and correction of different orders

Fig. 6. Comparison of corrected and uncorrected ranging results. (a) 800MHz RF power changes with moving distance; (b) uncorrected and corrected distance based on fourth-order polynomials are linearly fitted to reference distance of linear translation stage movement; (c) residuals after linear fitting