提出一种稳定的波长间隔可调谐的双波长单纵模环形光纤激光器.在复合环形谐振腔中，采用由数字微镜装置（DMD）滤波器和两个不同长度的次级环形谐振腔组成的多重滤波的方式来选择激光器的工作模式.其中，DMD滤波器可以从掺铒光纤的自发增益谱中任意选择两个波长并将它们耦合进光路中；次级环形谐振腔作为模式滤波器，可以保证激光器输出单纵模激射；利用非线性光子晶体光纤（HN-PCF）的四波混频（FWM）效应，使激光器输出均衡平稳的双波长激射.在室温条件下，不用移动实验装置中的任何器件，通过将位置不同的光栅映射在DMD滤波器上来实现双波长间隔可调谐，调谐范围为0.165 nm到1.08 nm，调谐步长为0.055 nm.

A stable single-longitudinal-mode dual-wavelength (SLM-DW) multiple ring fiber laser with a tunable wavelength spacing was proposed and demonstrated. In the multiple ring cavities, the mode selection is made by the tunable digital micro-mirror device (DMD) filter and two different length passive sub-ring cavities. The DMD filter can select and couple any two wavelengths from the gain spectrum of the erbium-doped fiber (EDF). The SLM lasing is guaranteed by the two sub-ring cavities which serve as a mode filter. The stable and uniform dual-wavelength oscillation is obtained by the highly-nonlinear photonic crystal fiber (HN-PCF), which can generate the four-wave-mixing (FWM) effective. By loading different gratings on the DMD filter without any mechanically shift, the tunable wavelength spacing from appropriately 0.165 nm to 1.08 nm within a tuning accuracy of 0.055 nm is achieved at room temperature.