Fig. 1: Lead-bismuth-gallate (PBG) graded-index multimode optical fiber characteristics.
From: Two octave supercontinuum generation in a non-silica graded-index multimode fiber
a Experimentally measured attenuation of the bulk PBG-81 (blue) and PBG-89 (red) constituent glasses. The attenuation of the fabricated GRIN fiber is shown in green. b Measured group refractive index ng of PBG-81 (blue dashed) and PBG-89 (red dashed). The calculated refractive index n using the extracted Sellmeier coefficients from the measured group index (see Methods) is shown as blue and red solid lines for PBG-81 and PBG-89, respectively. c Simulated 3D average refractive index distribution of the fiber structure. d Propagation constant difference Δβ of the first 30 modes (with respect to the fundamental mode) of the fiber with 80 μm core diameter and refractive-index profile as in c. e Dispersion profiles of the PBG fiber fundamental and selected higher-order LP modes. The inset in (e) shows a magnified view of the dispersion profile near the zero-dispersion region where the vertical dashed lines mark the position of the ZDW. f Spatial amplitude distribution corresponding to the dispersion profile of the modes shown in e.
