基于FPGA的可调谐光纤激光器频率锁定控制电路

Frequency locking control circuit for tunable fiber laser based on FPGA

根据PDH(Pound-Drever-Hall)稳频技术原理设计了基于FPGA的可调谐光纤激光器频率锁定控制电路,利用Matlab/Simulink建立频率误差信号解调电路模型,仿真结果表明能够输出频率误差信号。以FPGA为核心控制A/D采集光电探测器探测的信号,结合DDS(Direct Digital Synthesizer)技术在FPGA内部实现混频和低通滤波的功能,实验结果与仿真结果相符,能够解调出光纤激光器输出激光的频率锁定误差信号。根据此误差信号调节反馈电压,改变受压电陶瓷调谐的有源相移光纤光栅峰值谐振波长,实现对激光器的频率锁定,为光纤激光器稳频系统的集成化奠定了基础。

A frequency locking control circuit of tunable fiber laser based on FPGA is designed according to the principle of PDH frequency stabilization technology.The demodulation circuit model of frequency error signal is established by Matlab/Simulink,and the simulation results show that the frequency locking error signal can be output.FPGA is used as the core to control the A/D to collect the reflected light signal of photoelectric detector.Combined with DDS technology,the functions of mixing and low-pass filtering are realized inside the FPGA.The experimental results are consistent with the simulation results,and the frequency error signal of the output laser of the fiber laser can be demodulated.According to the error signal,the feedback voltage is adjusted,and the peak resonant wavelength of active phase-shifted fiber grating tuned by voltage electroceramics is changed to realize the frequency locking of the laser,which provides a foundation for the integration of fiber laser frequency stabilization system.