Fig. 2: detected photonic density of state (DOS) in (η, δ) space.
From: Topological band structure via twisted photons in a degenerate cavity
a, d, and g The coupling among the photonic angular momentum with η = 0, π/8, π/4, respectively. The coupling of SAM modes with different η are denoted as no lines, dashed lines and solid lines between nearby modes, respectively. b, e, and h. The normalized transmission intensity as a function of the normalization cavity detuning parameters βΔL/π and δ/π. c, f, and i The spectra of DOS when the gap closes and opens at different δ. The band gap areas are marked in gray.
