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

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 TM01 mode, azimuthally polarized TE01 mode, hybrid polarized HE21 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 HE21 and TM01 (/TE01) 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 HE21 mode and TM01 (or TE01) mode with unequal amplitude.