Skip to Main content Skip to Navigation
Theses

Contribution à l'étude des propriétés dynamiques et optique non linéaires des ferroélectriques de la famille KTiOPO4 par spectroscopie optique

Abstract : The topic of the present thesis is : "contribution to the study of dynamical and non-linear optical properties of ferroelectric crystals family of KTiOPO4 by optical spectroscopy". This work consist in the systematic study of vibrational properties of the ferroelectric potassium titanyl orthophosphate KTiOPO4 (KTP) and some of its isomorphous compounds. This family of substances is of vast interest owing to their exceptionnal non-linear properties used in frequencies conversion and electro-optical modulation. The first part of the work corresponds to the study of KTP crystal for various geometrical configurations of measurements by infrared (ir), brillouin and raman spectroscopy between 7 and 300K on the one hand and at high temperatures on the other hand. The spectra were analyzed in terms of internal and external vibrational modes and by taking into account coulomb interactions inducing modes mixing described by the model of Shapiro and axe (1973). The high temperature spectra exhibit a strong quasi-elasticscatterring going with the low frequency vibration mode; this central peak is interpreted by dielectric relaxation of Debye type model which has been connected to ion conduction dynamic. The same type of work is applied to isomorphous compounds such as KTiOPO4AsO4, titanyl orthophosphate solid solutionsand titanyl orthoarsenate solid solutions. The last part of the work is devoted to the two following studies : connecting the Raman efficiencies of the most polar modes, deduced for IR spectroscopy, with the electro-ptical coefficients; calculating, on the basis of Levine model, the contributions of different chemical bonds of KTP to optical non-linearities more precisely to Miller indices
Complete list of metadata

Cited literature [47 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01775427
Contributor : Administrateur Du Ccsd <>
Submitted on : Tuesday, April 24, 2018 - 3:31:49 PM
Last modification on : Wednesday, July 4, 2018 - 1:18:03 AM
Long-term archiving on: : Wednesday, September 19, 2018 - 12:35:39 PM

File

Mohamadou.Ballo.SMZ9316.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01775427, version 1

Collections

Citation

Ballo Mohamadou. Contribution à l'étude des propriétés dynamiques et optique non linéaires des ferroélectriques de la famille KTiOPO4 par spectroscopie optique. Science des matériaux [cond-mat.mtrl-sci]. Université Paul Verlaine - Metz, 1993. Français. ⟨NNT : 1993METZ016S⟩. ⟨tel-01775427⟩

Share

Metrics

Record views

230

Files downloads

119