Fig. 1. Superposition of polarization-degenerate modes (blue frame) in the same spatial distribution.

Fig. 2. Setup with four-channel off-axis holography.

Fig. 3. Simulation process.

Fig. 4. Parameter of vectorial laser and light intensity distribution. (a) Mode coefficient set in the simulation; (b) set values of the mode polarization states; (c) intensity of the test light; (d) intensity of the reference light.

Fig. 5. Off-axis hologram of 0° channel and its demodulation results. (a) Off-axis hologram; (b) local spectral distribution; (c) demodulation results of the light intensity; (d) demodulation results of the phase distribution.

Fig. 6. Light intensity distribution in the conjugated position of the fiber end and its MD reconstruction in the 0° channel. (a) Light intensity after virtual transmission; (b) MD coefficients; (c) reconstruction by MD.

Fig. 7. Simulation results of mode analysis. (a) Mode weights; (b) relative phase differences; (c) mode polarization states; (d) reconstruction after mode analysis.

Fig. 8. Experimental setup.

Fig. 9. Reference light intensity on each channel and its DOLP distribution. (a)–(d) Intensity of the reference light on different channels; (e) DOLP distribution of the reference light.

Fig. 10. Holograms in each channel and its demodulation results. (a)–(d) Holograms; (e)–(h) demodulation results of the intensity; (i)–(l) demodulation results of the phase.

Fig. 11. Mode analysis results. (a) Reconstruction by MD; (b) reconstruction by mode analysis; (c) mode coefficients; (d) polarization states.

Fig. 12. Similarities of different MD calculations.

Fig. 13. Mode analysis results based on the reference light on different polarization states. (a) Elliptic polarization; (b) linear polarization; (c) polarization analysis results based on the reference light on different polarization states.

Fig. 14. Effects of the remaining tilt and defocus aberrations on mode analysis.