基于FPGA的可调谐激光器控制电路设计

Design of tunable laser control circuit based on FPGA

摘要:

可调谐激光器是光纤光栅解调系统中最主要的部件之一，其输出波长和功率的稳定性影响整个解调系统的性能。文中对MG-Y可调谐激光器的调谐原理进行了分析，设计了一种基于FPGA的可调谐激光器控制电路。使用温度控制芯片ADN8834对MG-Y激光器进行温度控制，通过改变电流源的输出电流，控制激光器的输出波长。利用光谱分析仪采集激光器的输出波长，并对激光器的输出波长进行标定，制作“波长-电流”查询表。FPGA通过调用“波长-电流”查询表，实现激光器的波长在1527～1567 nm范围内以20 pm间隔连续线性扫描。同时搭建光纤布拉格光栅解调系统，验证了可调谐激光器解调光纤光栅中心波长的可行性。

Abstract:

Tunable laser is one of the most important components in the fiber Bragg grating demodulation system.The stability of its output wavelength and power affects the performance of the whole demodulation system. In this paper, the tuning principle of MG-Y tunable laser is analyzed, and a tunable laser control circuit based on FPGA is designed. The circuit uses a temperature control chip ADN8834 to control the temperature of the MG-Y laser, and controls output wavelength of the laser by changing the output current of the current source. The output wavelength of the laser is analyzed by spectrum analyzer, and the output wavelength of laser is calibrated, and the wavelength-current query table is made. The wavelength of the laser can be scanned continuously in the range of 1527 ~ 1567 nm at the interval of 20 pm by FPGA calling the wavelength-current query table. At the same time,a fiber Bragg grating demodulation system was built to verify the feasibility of the tunable laser to demodulate the center wavelength of the fiber grating.