Influence of composition and defects on the properties of transparent ceramics and crystals for laser and scintillator
applications.

Accordo Coop. Scientifica CNR / AVCR

Funded by: Consiglio Nazionale delle Ricerche (CNR)  
Calls: Accordo Coop. Scientifica CNR / AVCR
Start date: 2013-01-01  End date: 2015-12-31
Total Budget: EUR 15.000,00  INO share of the total budget: EUR 15.000,00
Scientific manager:    and for INO is: Toci Guido

Organization/Institution/Company main assignee: CNR – Istituto Nazionale di Ottica (INO)

other Organization/Institution/Company involved:
Institute of Physics, Academy of Science, Prague, Czech Republic
Istituto di Fisica Applicata “Nello Carrara”, IFAC-CNR, Sesto Fiorentino (FI)

other INO’s people involved:

Vannini Matteo


Abstract: Recently, Transparent Optical Ceramics (TOC) withdifferent compositions have reached a good level of development, often reaching anadequate quality for the realization of laser devices and scintillators. The influence ofcomposition and defects for the two kinds of applications is rather different. In lasermaterials, the most important characteristics are the low scattering losses due to theresidual porosity and interfacial secondary phases, the absence of quenchingmechanisms for the excited states of the lasing ion, as well as macroscopicthermomechanical properties (e.g. thermal conductivity, fracture toughness). Forscintillator applications other aspects are important such as the absence of trap states ordecay processes with long life time. The optimization of the composition andpreparation methods for the two kinds of applications can then be different. The generalaim of this project is to study the laser characteristics and the scintillation and luminescence properties on TOC and precursor powder samples with differentcompositions, in order to get useful information regarding stoichiometry, doping levelsand preparation methods optimized for the two applications, also by comparison withthe characteristics of the related single crystal samples.

INO’s Experiments/Theoretical Study correlated:
Characterization of new materials for Solid state sources

The Scientific Results:
1) Yb:Lu2SiO5 crystal: characterization of the laser emission along the three dielectric axes
2) A comparison of the laser performance of Yb3+:LuAG crystals with different doping levels
3) Experimental evidence of a nonlinear loss mechanism in highly doped Yb:LuAG crystal
4) A comparison of the laser performance of Yb3+: LuAG crystals with different doping levels
5) The role played on the Yb: LuAG laser performance by high doping levels and high ion excitation density
6) CW and quasi-CW laser performance of 10 at.% Yb3+:LuAG ceramic
7) Characterization of the lasing properties of a 5% Yb doped Lu2SiO5 crystal along its three principal dielectric axes