In this paper, a parallel polarization-beam-splitter-based fiber optic filter with adjustable channel spacing is proposed and demonstrated. The transmission characteristics of the proposed filter are simulated and analyzed using the transmission matrix theory. Simulation results show that the filter can generate three different channel spacings by adjusting different polarization controllers (PCs) in front of the polarization beam splitter (PBS). The experiment confirms the feasibility of a multi-wavelength fiber laser (MWFL) constructed based on this filter in achieving channel spacing switching. Its wavelength spacing can be switched between 0.46 nm, 0.66 nm, and 0.88 nm, matching the simulated results of the filter. The power fluctuations between the outputs of the three-channel spacing outputs are less than 1.17 dB, 0.89 dB, and 0.98 dB, and the wavelength fluctuations are less than 0.18 nm, 0.14 nm, and 0.13 nm, respectively.

该文提出并演示了一种基于平行偏振分束器的通道间距可调的光纤滤波器。利用传输矩阵理论对所提滤波器的传输特性进行了仿真和分析。仿真结果表明，该滤波器可以通过调整偏振分束器 （PBS） 前面的不同偏振控制器 （PC） 来产生三个不同的通道间距。实验证实了基于该滤波器构建的多波长光纤激光器 （MWFL） 实现信道间隔切换的可行性。其波长间距可在 0.46 nm、0.66 nm 和 0.88 nm 之间切换，与滤光片的模拟结果相匹配。三通道间隔输出输出之间的功率波动小于 1.17 dB、0.89 dB 和 0.98 dB，波长波动分别小于 0.18 nm、0.14 nm 和 0.13 nm。