Figure 2
From: Large-mode-area single-mode-output Neodymium-doped silicate glass all-solid photonic crystal fiber

Cross section of the end face of fiber made from silicate glass under different magnification.
From: Large-mode-area single-mode-output Neodymium-doped silicate glass all-solid photonic crystal fiber
Cross section of the end face of fiber made from silicate glass under different magnification.