Figure 4: Modes excited in a dielectric wakefield accelerator.
(a) Interferogram showing the autocorrelation of the coherent CCR generated by a single electron bunch in a 1 cm long dielectric wakefield accelerator structure. The central spike is due to prompt coherent diffraction radiation generated by structure exit and collection optics. (b) Spectral content of interferogram in (a), with the TM01 (422 GHz) and TM02 (1.27 THz) modes readily identifiable. Coherent diffraction radiation gives the broad peak near 1 THz. (c) Kramers–Kronig reconstruction of CCR (see Methods) in time domain from analysis of (a,b), plotted as the signal strength as a function of distance behind the driving beam, ζ=z−ct.
