Vector mode excitation in few-mode fiber by controlling incident polarization

Abstract The excitation of vector modes in a few-mode fiber by varying the polarization states of Gaussian incident beam at different off-axis conditions was investigated. As a result, the linearly polarized incidence orientated at four different off-axis conditions excited radially polarized TM 01 mode, azimuthally polarized TE 01 mode, hybrid polarized HE 21 mode, or linearly polarized two-lobe mode separately. Further, the left/right circularly polarized incidence excited linearly polarized two-lobe mode and the excited mode was interpreted as the combination of HE 21 and TM 01 (/TE 01 ) modes with equal amplitude. The left/right elliptically polarized incidence excited the two-lobe mode with the crescent conglutination between each pair of lobes and the excited mode was interpreted as the combination of HE 21 mode and TM 01 (or TE 01 ) mode with unequal amplitude.