LI Hong-ye, WAN Hong-dan, WANG Du-yi, et al. Optical Properties of Few-Mode Fiber with Non-Uniform Refractive Index[J]. 2016,(5):46-49. DOI: 10.13756/j.gtxyj.2016.05.014.
This paper studies optical properties of few-mode fibers with non-uniform refractive index profile
namely:the Ushape refractive index few-mode fiber and the bending two-mode and four-mode fiber.Finite element method is used to analyze the modal profile of these few-mode fibers.The U-shape refractive index few-mode fiber can support LP11 mode and suppress LP01 mode with a proper pump at 1 550 nm.The two-mode fiber and four-mode fiber can only support LP01 and LP11mode with a bending radius of 4cm and 2cm
respectively.Two-mode and four-mode Fiber Bragg Gratings(FBG)are also studied theoretically and experimentally.As to the two-mode FBG
LP11 mode distribution with a two-lobe shape is measured experimentally near a transmission wavelength of 1 549.79 nm.As to the four-mode FBG
the number of reflection peak wavelength is decreased with a lower bending radius.