Fig. 1. Block diagram of micro-ring resonator wavelength locking system based on digital signal processing

Fig. 2. Variation of output optical power of micro-ring resonator with heating power

Fig. 3. Flow chart of searching global optimal heating power based on differential evolution algorithm

Fig. 4. Flow chart of wavelength locking based on digital perturbation algorithm

Fig. 5. Physical drawing of experimental platform

Fig. 6. Evolution times of 500 experiments based on differential evolution algorithm to search the best heating power

Fig. 7. Wavelength lock experimental results based on digital perturbation algorithm. (a) Full-cycle sinusoidal perturbation digital signal; (b) variation of error signal and output optical power with heating power

Fig. 8. Changes in output optical power and heating power in 3 stages. (a) Output optical power; (b) heating power

Fig. 9. Experimental results with ambient temperature change of 5 ℃. (a) Variation of micro-ring resonator wavelength with temperature; (b) change of heating power when ambient temperature changes 5 ℃ in 0‒400 s