利用内插窄带双锥光纤滤波器的复合腔共振选模原理和近阈值运转状态下腔内自建可饱和吸收对双向共振模的去耦作用，研制成线宽小于４ＭＨｚ的双向、同时、同频、单纵模振荡的全固化掺铒光纤环形激光器，并实现了全光纤环形激光器旋转传感测量 By using the principle of resonant cavity mode selection and the decoupling effect of self-built saturable absorption in the near-threshold mode on the bi-directional resonant modes, we developed a bi-directional system with a linewidth of less than 4MHz. Meanwhile, Frequency, single longitudinal mode oscillation of the fully cured erbium-doped fiber ring laser, and realized all fiber ring laser rotation sensing measurement