Design and Characterization of Thulium-Doped Fiber with Depressed Cladding for Amplifiers Operating in the Region from L-Band to 1.8 µm

The current demands on optical communications are running up against their physical limits with the exponential increase in the volume of data transmitted over the Internet [1]. The increasing capacity requirements of optical transmission paths support the use of fiber amplifiers outside the standard spectral bands. For these purposes, existing aluminosilicate fibers can be used, which, unlike anti-resonant hollow-core fibers or hollow-core photonic crystal fibers, are more accessible in terms of manufacture as well as cost.