title: Low-threshold single-wavelength all-fiber laser generating cylindrical vector beams using a few-mode fiber Bragg grating.
abstract: We propose and demonstrate a low-threshold single-wavelength all-fiber laser generating cylindrical vector beams using a few-mode fiber Bragg grating. Both radially and azimuthally polarized beams have been generated with very good modal symmetry and polarization purity higher than 94%. The radially and azimuthally polarized modes can be switched by simply adjusting the polarization controllers built in the fiber laser cavity. This fiber laser operates at a single wavelength of 1053 nm with a 3 dB linewidth of less than 0.02 nm, signal-to-background ratio of more than 55 dB, and a threshold as low as 16 mW. A new method for the polarization purity measurement is also proposed.
authors.affiliation: Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Sun
authors.forename: Anting
authors.initials: A
authors.lastname: Wang
authors.forename: Lixin
authors.initials: L
authors.lastname: Xu
authors.forename: Chun
authors.initials: C
authors.lastname: Gu
authors.forename: Zhongxi
authors.initials: Z
authors.lastname: Lin
authors.forename: Hai
authors.initials: H
authors.lastname: Ming
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Zhan