Fig. 3: Theoretical and experimental band structures.
From: Topological band structure via twisted photons in a degenerate cavity
a, c, and e Theoretically calculated energy band spectra with δ = 0, π/12 and π/6 when η = π/4, respectively. The x (y)-axis represents the normalized quasimomentum k/π (quasienergy Ek/π). The coupling among optical angular momentum are shown in the inserts, in which the increasing strength is denoted as no lines, dashed lines and solid lines between nearby modes, respectively. b, d, and f The corresponding experimental energy band of δ = 0, π/12, and π/6 when η = π/4, respectively. The x (y)-axis represents the normalized cavity detuning βΔL/π (the parameter \({k}_{\exp }/\pi\)).
