Wave dispersion analysis. Top panel a: wave dispersion ω(k)/ω_pe at the final times of the linear phase. From figure simulation (see Table 2 for parameters). The diagnostic was performed on the δB_z component between tΩ_ci = 95 ant tΩ_ci = 96.6 (at the end of the linear phase of the instability). Electromagnetic light-wave branch with left and right-handed polarisation is easily identifiable. At low ω < Ω_ce the Whistler branch is clearly seen as well (theoretical dispersion line over plotted with dashed line). Plasma emission at ω = ω_pe is observed and the second harmonic can be observed as well, especially in the brighter zone where it intersects the EM wave. Bottom panel b: I₊(k) spectrum at saturation from Fid simulation. It is the same spectrum as in Fig. 5 but plotted using linear x-axis scale and wavenumber plotted in units of $d_{\mathrm{e}}^{-1}$. This improves the visibility of the high-k part of the spectrum.