575818.fig.003a
(a)
575818.fig.003b
(b)
575818.fig.003c
(c)
575818.fig.003d
(d)
Figure 3: (a) SEM image of the fabricated chalcogenide PCF, (b) optimal gain , (c) optimal length , and (d) noise figure versus signal wavelength λ s for three different input pump power levels:  mW (dot curve),  mW (broken curve), and (0) = 300 mW (full curve). Input signal power (0) = 0.1 μW, erbium concentration = 5.76 1024 ions/m3, and doped region radius = 5 μm [19, 25].