Fig. 1. Automatic laser frequency stabilization device based on modulation transfer spectroscopy

Fig. 2. Overall scheme of the modulation transfer spectral demodulation module

Fig. 3. Physical diagram of the modem module device

Fig. 4. PD amplification circuit

Fig. 5. MTS error signal

Fig. 6. Schematic of laser frequency locking error signal

Fig. 7. Diagram of laser frequency fast locking scheme

Fig. 8. Laser frequency long⁃term locking diagram

Fig. 9. Plot of laser frequency re⁃locking data results

Fig. 10. Gravimetric tide map