title: Linearly polarized orbital angular momentum mode purity measurement in optical fibers.
abstract: We presented a simple method for measuring the mode purity of linearly polarized orbital angular momentum (OAM) modes in optical fibers. The method is based on the analysis of OAM beam projections filtered by a polarizer. The amplitude spectrum and phase spectrum of a data ring derived from the beam pattern are obtained by Fourier transform. Then the coefficients of the mixed electric field expression can be determined and the mode purity can be obtained. The proposed method is validated and it is experimentally demonstrated in a two-mode fiber.
authors.forename: Youchao
authors.initials: Y
authors.lastname: Jiang
authors.forename: Guobin
authors.initials: G
authors.lastname: Ren
authors.forename: Haisu
authors.initials: H
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Tang
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Yue
authors.initials: Y
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Jian
authors.forename: Shuisheng
authors.initials: S
authors.lastname: Jian