提出一种基于高双折射光子晶体光纤与光纤环的超宽带可调谐微波光子滤波器.以多波长光纤激光器作为光源, 向高双折射光子晶体光纤内填充温敏液体, 通过改变填充温敏液体的温度, 高双折射光子晶体光纤可具有不同的双折射, 得到不同波长间隔的激光, 从而使微波光子滤波器具有不同的自由频谱范围.当温度的变化范围为20~80℃时, 仿真测得微波光子滤波器自由频谱的变化范围为2.49~39.9 GHz.引入光纤环构建级联型微波光子滤波器, 滤波器的主旁瓣抑制比可提高到33.6 dB, Q值可达到499, 提高了滤波器的频率选择性.

An ultra wideband tunable microwave photonic filter based on high birefringence photonic crystal fiber and fiber ring was proposed. The multi-wavelength fiber laser was used as the light source, and the high birefringence photonic crystal fiber was filled with temperature-sensitive liquid. The high birefringence photonic crystal fiber could own different birefringence by varying the temperature of temperature-sensitive liquid, and the laser output with different wavelengths was obtained, making the microwave photonic filter have different free spectral range. The simulating results show that when the temperature is changing from 20℃ to 80℃, the free spectral range of filter has the range of 2.49 GHz to 39.9 GHz. By introducing the fiber ring cascade in the microwave photonic filter, the main sidelobe suppression ratio of the filter can be raised to 33.6dB and the maximum Q-value of 499 can be obtained, which improve its frequency selectivity effectively.