Search

Double-clad optical fiber with a multi-ring core profile doped with thulium and holmium fabricated by Modified Chemical Vapor Deposition Chelate Doping Technology (MCVD-CDT) is presented. The measured Tm 2 O 3 and Ho 2 O 3 complexes' weight concentrations were 0.5% and 0.2% respectively. Numerical analyses show weakly guiding conditions and 42.2 µm of MFD LP 01 at 2000 nm. The low NA numerical aperture (NA = 0.054) was obtained for the 20/250 µm core/cladding ratio optical fiber construction. The emission spectra in the range of 1.6-2.1 µm vs. the fiber length are presented. The full width at half maximum (FWHM) decreases from 318 to 270 nm for fiber lengths from 2 to 10 m. The presented fiber design is of interest for the development of new construction of optical fibers operating in the eye-safe spectral range., (© 2023. Springer Nature Limited.)

Fluoroindate glasses co-doped with Pr 3+ /Er 3+ ions were synthesized and their near-infrared luminescence properties have been examined under selective excitation wavelengths. For the Pr 3+ /Er 3+ co-doped glass samples several radiative and nonradiative relaxation channels and their mechanisms are proposed under direct excitation of Pr 3+ and/or Er 3+ . The energy transfer processes between Pr 3+ and Er 3+ ions in fluoroindate glasses were identified. In particular, broadband near-infrared luminescence (FWHM = 278 nm) associated to the 1 G 4  →  3 H 5  (Pr 3+ ), 1 D 2  →  1 G 4  (Pr 3+ ) and 4 I 13/2  →  4 I 15/2  (Er 3+ ) transitions of rare earth ions in fluoroindate glass is successfully observed under direct excitation at 483 nm. Near-infrared luminescence spectra and their decays for glass samples co-doped with Pr 3+ /Er 3+ are compared to the experimental results obtained for fluoroindate glasses singly doped with rare earth ions.