(a–b) Experimental spectra and (c–d) results of numerical simulations at the input (Sp1, orange curve) and at the output (Sp6, black curve) of the fiber system, at the input of the transition 1 (Sp2, blue curve), 1 cm before the input of the ONF (Sp3, green curve), at the input of the nanofiber (Sp4, red curve), and at the end of the nanofiber (Sp5, cyan curve). Spectra in (b) and (d) are vertically shifted for clarity. DW, dispersive wave.