Measurements of the nonlinear refractive index of freestanding porous silicon layers at different wavelengths

Authors
Lettieri, S Maddalena, P Odierna, LP Ninno, D La Ferrara, V Di Francia, G
Citation
S. Lettieri et al., Measurements of the nonlinear refractive index of freestanding porous silicon layers at different wavelengths, PHIL MAG B, 81(2), 2001, pp. 133-139
Citations number
25
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICSELECTRONIC OPTICAL AND MAGNETIC PROPERTIES
ISSN journal
13642812 → ACNP
Volume
81
Issue
2
Year of publication
2001
Pages
133 - 139
Database
ISI
SICI code
1364-2812(200102)81:2<133:MOTNRI>2.0.ZU;2-I
Abstract
Measurements of the nonlinear refractive index n(2) of a high-porosity free standing porous silicon sample are reported at different laser wavelengths by means of the z-scan technique. The results show a negative below-gap non linear refractive index, so that thermal contributions to the observed effe cts can be reasonably excluded. Values for n(2) of the order of 10(-9) esu are here reported. These results are compatible with the hypothesis of an e nhancement of optical nonlinearities due to quantum confinement of carriers in nanocrystals present in the material.