Growth, optical characterization and evaluation of laser properties of Nd:LaF3 crystal

Int J of Appl Glass Sci

Balda

Fernández

et al. 2017

Transparent glass ceramic (GC) films and self-supported layers of composition 80SiO 2 -20LaF 3 doped with Nd 3+ were prepared by sol-gel method for the first for up-conversion. 19,20 But MQ method presents some limitations such as the high temperature of processing that causes fluorine loss by evaporation. Moreover, phase separation is commonly produced during the quenching, thus limiting the possibility to obtain homogenous materials with high optical quality. Therefore, many efforts were concentrated to prepare oxyfluoride materials by sol-gel method. [21][22][23][24][25][26][27][28][29][30][31] This process allows obtaining purer materials, and compositions impossible or extremely difficult to --

Section: Resultssupporting

confidence: 72%

Section: Iðtþdtsupporting

confidence: 69%

80SiO₂‐20LaF₃ oxyfluoride glass ceramic coatings doped with Nd³⁺ for optical applications

Int J of Appl Glass Sci

Balda

Fernández

et al. 2017

“…The spectrum obtained at 786 nm displays a more resolved structure which indicates a crystalline environment for Nd 3+ ions, whereas the one obtained under excitation at 802 nm exhibits an inhomogeneous broadened band similar to the glass sample. The emission spectrum obtained under excitation at 786 nm is similar to the one obtained in pure LaF 3 crystals [20]. Moreover, the excitation spectra obtained by collecting the luminescence at 1039 and 1057 nm also show the presence of different environments for Nd 3+ ions.…”

Section: Site-selective Luminescencesupporting

confidence: 73%

Site-resolved emission of Nd3+-doped oxyfluoride nano glass-ceramics

Balda

Optical Components and Materials XV

Velázquez

et al. 2018

Transparent oxyfluoride glass-ceramics obtained by the adequate heat treatment of Nd 3+ -doped glass with composition SiO 2 -Al 2 O 3 -Na 2 O-LaF 3 are investigated. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HR-TEM) show that the precipitated nanocrystals are LaF 3 with a crystal size between 9-12 nm. Furthermore, energy dispersive X-ray (EDX) analysis shows the incorporation of Nd 3+ ions into the LaF 3 nanocrystals. Site-selective and time-resolved emission and excitation spectra of the 4 F 3/2 and 4 F 5/2 states, allows to unambiguously isolate the emission of Nd 3+ ions in LaF 3 nanocrystals which shows well defined spectra, similar to those obtained for pure LaF 3 crystal.

“…In particular, the effect of Nd 3+ ions on the kinetics of crystallisation has been studied and the possibility to selectively separate the emission of Nd 3+ ions in the glass matrix from those embedded in LaF 3 nanocrystals is presented. Site-selective emission and excitation spectra together with the different lifetime values of the 4 F 3/2 state depending on the excitation and emission wavelengths allows the emission of Nd 3+ ions in LaF 3 nanocrystals to be unambiguously identified which shows extremely well defined spectra similar to those obtained for pure LaF 3 crystals [37], [38] and [39].…”

Section: Introductionmentioning

confidence: 99%

Selective excitation in transparent oxyfluoride glass-ceramics doped with Nd3+

Journal of the European Ceramic Society

Velázquez

Mather

et al. 2017

Transparent oxyfluoride nano-glass-ceramics have been prepared by melting-quenching and doped with five different Nd 3+ concentrations (0.1-2 mol%) to obtain the most efficient 4 F 3/2  4 I 11/2,13/2 emission. It was observed by differential thermal analysis (DTA) that the addition of Nd 3+ does not affect the crystallization mechanism which corresponds to a diffusioncontrolled volumetric process that starts from a constant number of nuclei. Nevertheless, the presence of the dopant affects the kinetics due to the progressive increase of T g on increasing the Nd 3+ content. LaF 3 crystals with a size between 9-12 nm are obtained after heat treatments at T g + 20-80 °C as confirmed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HR-TEM). Energy dispersive X-ray (EDX) analysis shows the incorporation of Nd 3+ ions into the LaF 3 nano-crystals. Judd-Ofelt analysis from the absorption spectra further demonstrate the incorporation of Nd 3+ ions into the fluoride phase and the most relevant parameters such as radiative lifetime and stimulated emission cross-section are calculated. A detailed optical characterisation clearly shows that Nd 3+ ions in the glass-ceramics are incorporated in both crystalline and amorphous phases. Low temperature site-selective emission and excitation spectra, together with the different lifetime values of the 4 F 3/2 state depending on the excitation and emission wavelengths, allow emission from Nd 3+ ions in the LaF 3 nanocrystals to be identified and correlated with the structural properties. As the Nd 3+ concentration is increased beyond 0.1 mol%, a stronger quenching of lifetime is observed for Nd 3+ ions residing in LaF 3 crystals than for those dispersed in the glass matrix. This strong concentration quenching is explained by the much higher concentration of Nd 3+ ions in the crystalline phase with respect to that in the glass matrix.