Enhanced NIR emission from nanocrystalline LaF3:Ho3+ germanate glass ceramics for E-band optical amplification

Nanocrystalline LaF3 germanate glass ceramics were prepared and used as host for optically active Ho3+ ions. LaF3 crystallites precipitate by internal nucleation with sizes in the range of 7-17 nm. During crystallization, Ho3+ is incorporated into the fluoride lattice on La3+ sites, leading to reduced probability of multiphonon relaxation and, hence, significantly enhanced emissions within 1300-1440 and 14001550 nm wavelength range. Excited state absorption spectra, stimulated emission spectra and spectral gain coefficients of the (S-5(2), F-5(4)) -> I-5(5) transition indicate suitability of the material for E-band optical amplification. (C) 2012 Elsevier B. V. All rights reserved.