Research on laser frequency locking technology based on temperature and PZT control

Aiming at the application requirement of resonator fiber optic gyroscopes, a frequency tracking and locking control scheme based on laser temperature and PZT control is proposed in this paper. By taking advantages of the large range of laser temperature tuning as well as the high precision and high dynamicity of PZT tuning, tracking of the fiber laser’s central frequency to the fiber ring resonator’s resonance frequency is realized. Typical transmission resonant curve is simulated by mathematical methods. Hardware design, algorithm simulations of temperature and PZT control scheme are carried out. The influence of control parameters on tracking stability is analyzed. The development of laser frequency tracking systems is assembled. The high-precision and long-time tracking of laser’s central frequency to resonance frequency is realized successfully. The locking precision is low to 4.8×10-9 over one hour under room temperature. The locking precision is low to 9.74×10-8 over 5.5 hours under variable temperature. This work has laid an important foundation for improving the long-term performance of resonator fiber optic gyroscopes.