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

Abstract Nanocrystalline LaF 3 germanate glass ceramics were prepared and used as host for optically active Ho 3+ ions. LaF 3 crystallites precipitate by internal nucleation with sizes in the range of 7–17 nm. During crystallization, Ho 3+ is incorporated into the fluoride lattice on La 3+ sites, leading to reduced probability of multiphonon relaxation and, hence, significantly enhanced emissions within 1300–1440 and 1400–1550 nm wavelength range. Excited state absorption spectra, stimulated emission spectra and spectral gain coefficients of the ( 5 S 2 , 5 F 4 ) →  5 I 5 transition indicate suitability of the material for E-band optical amplification.