ZHANG Li-li,ZHANG Xia,BAI Cheng-lin.Study on the effect of ellipticity and misalignment on OAM modes in a ring fiber[J].Optoelectronics Letters,2018,14(3):204-208 Study on the effect of ellipticity and misalignment on OAM modes in a ring fiber Author Name Affiliation ZHANG Li-li  Key Laboratory of Optical Communications Science and Technology in Shandong Province, School of Physics Science and Information Technology, Liaocheng 252059, China  ZHANG Xia  Key Laboratory of Optical Communications Science and Technology in Shandong Province, School of Physics Science and Information Technology, Liaocheng 252059, China  BAI Cheng-lin  Key Laboratory of Optical Communications Science and Technology in Shandong Province, School of Physics Science and Information Technology, Liaocheng 252059, China  Abstract:       Based on the optical fiber mode theory and employing the expertized software COMSOL, we study the effect of ellipticity and misalignment on the effective refractive indices, walk-off and intensity distribution of the even and odd eigenmodes that form the basis of the orbital angular momentum (OAM) modes in a ring fiber. Our results show that the effective refractive index difference and the walk-off increase with the ellipticity and misalignment, thus reducing the stability of the OAM modes. We find that the misalignment has a greater impact on the OAM modes than the ellipticity, and both the misalignment and ellipticity affect the lower-order OAM modes more significantly, suggesting that the higher-order OAM modes are more stable during propagation. Hits: 3940 Download times: 0 View Full Text    Download reader