Fig. 5

OAM spectrum analyzing for multi-ring OAM beams. a The schematic setup to generate two-fold multiplexed multi-ring OAM beams. QWP, quarter wave plate; P, polarizer. The two SLMs are encoded by two different holograms to generate |p₁, −l₁⟩ = |0, −2⟩ and |p₂, l₂⟩ = |2, 3⟩ respectively. By rotating HWP3, the intensity proportion of the two OAM components be adjusted. b The experimentally recorded intensity profile of two-fold multiplexed multi-ring OAM beams, and their corresponding simulation results. c The simulatively analyzed OAM spectra versus fast axis angle θ of HWP3. d The corresponding experimentally analyzed OAM spectra of (c). e The intensity proportion of OAM components |0, −2⟩ and |2, 3⟩ versus fast axis angle θ of HWP3