基于多波长激光器的带通微波光子滤波器设计

提出了一种基于多波长光纤激光器的可调谐的带通微波光子滤波器。它以可调谐多波长光纤激光器作为光源,将相位调制器和色散器件相结合,通过在普通单模光纤中相位调制到强度调制的转换效应消除了低频谐振峰实现了带通微波光子滤波器。利用双折射光纤环镜输出谱中的一个窗口对多波长激光信号频谱进行加窗处理,使微波光子滤波器的边瓣抑制比提高了约11dB。通过调节多波长光纤激光器中的偏振控制器可以使输出多波长激光信号的相邻波长间隔得到调节,从而结合普通单模光纤的色散延时作用可以使微波光子滤波器的通带中心频率在7.66GHz范围内调谐。

Design of Tunable Bandpass Photonic Microwave Filter Based on Multi-Wavelength Fiber Laser

A tunable bandpass microwave photonic filter (MPF) based on multi-wavelength fiber laser (MWFL) which is used as the light source is proposed and demonstrated. The combination of the phase modulator and the dispersion devices convert the phase modulation to intensity modulation in the ordinary single-mode fiber, and it eliminates the low-frequency resonant peak thus a new bandpass filter is realized. By using one of the birefringent fiber loop mirror output windows for the apodization of the multi-wavelength signal, the main lobe to sidelobe suppression ratio of the MPF is raised about 11 dB. The wavelength interval of the MWFL can be adjusted by tuning the polarization controllers (PC) in it. The time delay between adjacent wavelengths is changed when the laser signal passes through the ordinary single-mode fiber because of the dispersion in it thus the central frequency of the band pass MPF is tuned within 7.66 GHz.