Fig. 1. Schematic of the experimental setup and atomic energy levels. M, mirror; HWP, half-wave plate; QWP, quarter-wave plate; L, lens; PBS, polarization beam splitter; PD, photodetector; SMF, single-mode fiber; VRP, vortex retarder plate; CCD, charge-coupled device camera; MFS, magnetic field shielding; PM, projection measurement; SAS, saturated absorption spectroscopy; VBG, vector beam generation.

Fig. 2. Experimental results of the radially polarized beam in presence of TMF. (a) Intensity and polarization distribution without atoms. (b)–(h) Intensity distributions after passing through atoms under vertical TMF of varying strength: BTMF=0, 23, 61, 123, 146, 206, and 230 mG, respectively. (i) Dependence of transmitted intensity for two selected regions against BTMF.

Fig. 3. Experimental results of the radially polarized beam in presence of an LMF. (a)–(f) Intensity distributions after passing through the atom vapor under the varied LMF: BLMF=0, 50, 100, 120, 160, and 200 mG, respectively. (g) Dependence of transmitted intensity for whole beam against the BLMF.

Fig. 4. Transmission profiles as functions of TMFs alignment. (a) and (b) Intensity and polarization distributions for vertical and diagonal TMF alignment. (c) Image axis of the transmission profile as a function of TMF alignment. Insets: examples of observed transmission profiles.

Fig. 5. Experimental results of the radially polarized beam in presence of the spatial magnetic field with fixed strength (|B|=230  mG). (a) |B|=0  mG. (b)–(f) Transmitted patterns with θ=π/6,π/4,π/3,5π/12,π/2, respectively. (g) Polar plots for patterns at different angle θ at the radius indicated in (f).

Fig. 6. Polarization and intensity profiles for VBs with different polarization topological charges m=1 (top row) and m=2 (bottom row). (a) and (d) Profiles of VBs without atoms. (b) and (e) After passing through atoms in the absence of a magnetic field. (c) and (f) Petal-like patterns under BTMF=230  mG. (g) Polar plots of the absorption profile in (c) along the radius of largest contrast.

Fig. 7. Excitation scheme for (a) the LMF and (d) the TMF. (b) Coherent dark state and (c) decoherent state induced by Zeeman splitting. Bare dark state (e) without and (f) with Zeeman splitting. In presence of the magnetic field, magnetic sublevels are shifted by an amount μBgFmFB, where μB is the Bohr magneton, gF is the Landé-factor, and B is the magnetic field strength.