title: Broadband mode division multiplexer using all-fiber mode selective couplers.
abstract: We report an all-fiber mode division multiplexer formed with cascaded mode selective couplers with significantly broadened bandwidth potentially spanning S, C and L band. This was achieved by matching the effective refractive indices over a wide wavelength range for the few mode fiber and the single mode fiber used in the coupler. The multiplexer provides high coupling efficiency (>55% for the worst case) for the 4 spatial modes over the entire wavelength range of 1515-1590 nm. The all-fiber construction provides mechanical stability. Experimental results for the coupling efficiency and the mode extinction ratio for each spatial mode are presented along with the far field radiation patterns.
authors.forename: Kyung Jun
authors.initials: KJ
authors.lastname: Park
authors.forename: Kwang Yong
authors.initials: KY
authors.lastname: Song
authors.forename: Young Kie
authors.initials: YK
authors.lastname: Kim
authors.forename: Jae Hyeon
authors.initials: JH
authors.lastname: Lee
authors.forename: Byoung Yoon
authors.initials: BY
authors.lastname: Kim