Extended Data Fig. 4: Chiral mode excitation.
From: Twisted optical fibres as photonic topological insulators
a, Local Chern marker as a function of rescaled cutoff propagation constant Δβ/C. The two plateaus indicate the regions of the mode structure that contain topological modes with either a positive or negative Chern marker. b, Mode overlap between our initial excitation in the \({\mathcal{C}}=1\) regime (shown in the inset) and the rest of the twisted fibre supported modes. In the inset, the initial excitation is plotted. The intensity of the plotted mode is shown by saturation and the hue corresponds to the phase. c, Mode overlap between our initial excitation in the \({\mathcal{C}}=-1\) regime (shown in the inset) and the rest of the twisted fibre supported modes. In the inset, the \({\mathcal{C}}=-1\) initial excitation is plotted with saturation corresponding to intensity and hue representing phase.
