Upconversion fluorescence property of Er3+/Yb3+-codoped novel bismuth-germanium glass

Infrared-to-visible upconversion fluorescence property of Er3+/Yb3+ codoped novel bismuth-germanium glass under 975 nm LD excitation has been studied. Intense green and red emissions centered at 525, 546 and 657 nm, corresponding to the transitions H-2(11/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2), and F-4(9/2) -> I-4(15/2), respectively, were observed at room temperature. The quadratic dependence of the 525, 546 and 657 nm emissions on excitation power indicates that a two-photon absorption process occurs. The structure of the bismuth-germanium glass has been investigated by peak-deconvolution of FT-Raman spectrum, and the structural information was obtained from the peak wavenumbers. This novel bismuth-germanium glass with low maximum phonon energy (similar to 750 cm(-1)) can be used as potential host material for upconversion lasers. (c) 2005 Elsevier Ltd. All rights reserved.

Ariketa fisikoaren onurak 9 eta 12 urte arteko umeen bizkarreko arazoetan: 12 asteko programa espezifiko baten proposamena

Bizkarreko arazoetan jarduera fisikoak duen garrantzia aztertzen da lan honetan, eta horrez gain, hamabi asteko jarduera fisikoko programa baten proposamena aurkezten da.

Campagne Chalci 80-01 (20/8/1980-10/9/1980): résultats des chalutages

One additional Chalci campaign that, in line with the previous Chalci campaigns 78-01, 78-02, and 79/01, has as its major objective the trawl exploration of the Ivoirian continental shelf at the depth of 10 to 120 metres.

Un "lapsus calami" (K.9.2) y la escritura redundante en la Celtiberia

Este artículo se ha realizado dentro del Proyecto de Investigación «Identidades y diversidad cultural en la Hispania Antigua: Bilingüismo y Cultura Epigráfica» (HUM 2006-13424-C04-02/Filo).