Photonic bandgap properties of nanoporous silicon microstructures^*

¹ Laboratoire de Spectrométrie Physique, Université J. Fourier Grenoble 1 (CNRS UMR 5588), BP 87, 38402 Saint Martin d'Hères, France
² Dipartimento di Fisica - sezione INFM di Cagliari, Citt. Universitaria, Strada Prov. le Monseratto-sestu Km 0.700, 09042 Monserrato (CA), Italy

Corresponding author: Patrick.Ferrand@ujf-grenoble.fr

Received: 11 January 2001
Accepted: 11 May 2001
Published online: 15 October 2001

Abstract

We report the recent progress in the structuration of nanoporous silicon at a submicronic scale. Multilayered periodic structures, with low-roughness interfaces, and an index contrast of 0.6 are reported. Their strong photonic bandgap properties are demonstrated by the measurement of a reflectance up to 99.64% ± 0.01%, by mean of ring-down spectroscopy. This property is the base of a novel structure allowing an efficient guiding of light in a low-index layer. The submicronic structuration of the optical index of a planar waveguide along one direction of plane is also described, and a realistic map of the optical index, demonstrating a index contrast of 0.5, is unambiguously deduced from transmission spectra.