提出了一种改进环光纤结构,在原环光纤中引入一高折射率层,利用模式重组效应,增大了轨道角动量模式之间的有效折射率差,减弱了模式间的简并现象。通过数值仿真,对该改进环光纤结构的参数进行了优化设计,最终实现了不同轨道角动量模式间约10-3的有效折射率差,从而可以有效地抑制传输过程中的模间串扰,改善环光纤中轨道角动量模式的传输性能。 An improved ring fiber structure was proposed. A high refractive index layer was introduced into the original ring fiber. The mode recombination effect was used to increase the effective refractive index difference between the orbital angular momentum modes and reduce the degeneracy among the modes. Through numerical simulation, the parameters of the improved ring fiber structure are optimized, and the effective refractive index difference of about 10-3 between different orbital angular momentum modes is finally achieved, which can effectively suppress the inter-modal crosstalk in the transmission process and improve Transmission Performance of Orbit Angular Momentum in Ring Fiber.