Tuning the nanostructuration of Nb2O5 oxides for specific optical non linear properties

Anne Teissier 1,2Valérie Keller Spitzer 1Jean-Pierre Moeglin 2Yves Lutz 2

1. Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse, Louis Pasteur University, CNRS (LMSPC-ULP-), 25 rue Becquerel, Strasbourg 67087, France
2. Institut de recherches de Saint-Louis (ISL), 5 rue du Général Cassagnou, Saint-Louis 68300, France

Abstract

With the development of high-power laser sources, the study and design of optical limiting systems that protect fine components like eyes and sensors have gained importance. The hazard, due to the narrow divergence of the laser beam and the resulting tightly-focussed spot on the sensor requires a protection in some regions of the spectra, including the visible and infrared domains. This protection could be thought as a material that rapidly interrupts or limits the transmission of the beam to a safe level when reaching very high intensities.

Nanomaterials like nano-oxides should be promising candidates for limiting materials. Recent studies have shown that carbon nanotubes exhibit efficient properties for limiting systems in the near infrared domain. The aim of our study is to develop a protective system in the far infrared domain, using nano-oxides synthesised via sol-gel methods, allowing to obtain advanced and functional powders and coatings of high optical quality. Sol-gel process exhibits the advantages of being an easily modified synthesis of nano-oxides making possible to tune many structural and morphological parameters. Our aim is to correlate the optical response of these nanoparticles at the nanoscale as functions of these various preparation parameters.

Niobium(V) oxide (Nb2O5) powders were prepared by the sol-gel procedures from niobium ethoxide, Nb(OC2H5)5.

Non linear optical limiting properties of these oxides were investigated using the Z-scan method which enables to measure both the nonlinear refractive index and absorption coefficient.

SamplesA_B_valerie.jpg

Fig. 1 Sample A : Z-scan results and SEM Fig. 2 Sample B : Z-scan results and TEM

These nano-oxide Nb2O5 materials show interesting optical non linear properties (fig 1 and 2) depending on the structural, compositional and morphological nanoscale characteristics, which can be finely tuned using different modifications and variations of the Nb2O5 sol-gel synthesis.

 

Presentation: Oral at E-MRS Fall Meeting 2007, Symposium A, by Anne Teissier
See On-line Journal of E-MRS Fall Meeting 2007

Submitted: 2007-01-15 16:30
Revised:   2009-06-07 00:44