Search results for "Rare-Earth ions"
showing 4 items of 4 documents
Role of the thermal treatment on the microstructure of YAGG nanopowders prepared by urea glass route
2023
Yttrium aluminium gallium garnet (YAGG, Y3Al2Ga3O12) doped with rare-earth ions has drawn large attention owing to its optical properties with applications ranging from persistent luminescent phosphors to nanothermometers. Herein, three different YAGG materials were synthesized via the urea glass route followed by thermal treatment, relatively undoped; doped with Ce3+, Cr3+, and Nd3+; and doped with Ce3+, Cr3+, and Yb3+. The garnet formation was studied in situ upon thermal treatment from 300 to 1000 ◦C using synchrotron powder diffraction. Our results show that with this method, the onset of formation of the garnet is about 860 ◦C, with comparable cell parameters for both undoped and doped…
Experimental and theoretical study on the optical properties of LaVO4 crystals under pressure
2018
We report optical absorption and luminescence measurements in pure and trivalent neodymium (Nd3+) doped LaVO4 crystals up to 25 GPa. Nd3+ luminescence has been employed as a tool to follow the structural changes in the crystal. We also present band-structure and crystal-field calculations that provide the theoretical framework to accurately explain the observed experimental results. In particular, both optical absorption and luminescence measurements evidence that a phase transition takes place close to 12 GPa. They also provide information on the pressure dependence of the band-gap as well as the emission lines under compression. We found drastic changes in the optical properties of LaVO4 …
Design of Radiation-Hardened Rare-Earth Doped Amplifiers through a Coupled Experiment/Simulation Approach
2013
International audience; We present an approach coupling a limited experimental number of tests with numerical simulations regarding the design of radiation-hardened (RH) rare earth (RE)-doped fiber amplifiers. Radiation tests are done on RE-doped fiber samples in order to measure and assess the values of the principal input parameters requested by the simulation tool based on particle swarm optimization (PSO) approach. The proposed simulation procedure is validated by comparing the calculation results with the measured degradations of two amplifiers made with standard and RH RE-doped optical fibers, respectively. After validation, the numerical code is used to theoretically investigate the …
Coupled experiment/simulation approach for the design of radiation-hardened rare-earth doped optical fibers and amplifiers
2011
We developed an approach to design radiation-hardened rare earth -doped fibers and amplifiers. This methodology combines testing experiments on these devices with particle swarm optimization (PSO) calculations. The composition of Er/Yb-doped phosphosilicate fibers was improved by introducing Cerium inside their cores. Such composition strongly reduces the amplifier radiation sensitivity, limiting its degradation: we observed a gain decreasing from 19 dB to 18 dB after 50 krad whereas previous studies reported higher degradations up to 0°dB at such doses. PSO calculations, taking only into account the radiation effects on the absorption efficiency around the pump and emission wavelengths, co…