Design of ring-assisted few-mode fiber with low loss for improved mode-division multiplexing

Abstract

We report a ring-assisted few-mode fiber design with large mode effective index difference (△n eff ) and low loss. By introducing the low-index ring-assisted structure in the cladding, the effective indexes of LP 11 , LP 21 and LP 02 modes can be greatly reduced, while the effective index of LP 01 mode is almost unaffected. Also, we find that introducing multiple ring-assisted structures will help reduce loss. The proposed few-mode fiber has potential application value for improved mode-division multiplexing optical fiber communication system.