Figure 2

Measured spectral distribution of the output light after using a krypton-filled hollow core fiber at various output pulse energies (given in the plots). (a) Antiresonant fiber including a pressure gradient (low-pressure side facing input, pressure at output: 6 bar). (b)-(f) Homogenously filled fiber at a pressure of 6 bar. (g)-(p) Far field images (in false colors) of the output mode at various wavelengths for an output energy of 12.1 μJ (at a constant pressure) are shown on the right side of the figure (numbers indicate the central wavelengths (in nm) of the bandpass filters).