Fig. 1. Schematic of experimental setup

Fig. 2. Relationship between 397.5 nm double frequency laser power and 795 nm fundamental laser power

Fig. 3. Relationship between double frequency laser power and crystal temperature at fundamental laser power of 280 mW

Fig. 4. Bragg diffraction of acousto-optic frequency shifter

Fig. 5. Diffraction efficiency of acousto-optic frequency shifter versus the radio-frequency power

Fig. 6. Laser power spectral density before and after locking feedback system

Fig. 7. Change of laser power before and after locking feedback system by using voltage meter. (a) Before locking; (b) after locking