999 resultados para 940


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Infrared (1.2-1.6 mum) luminescence in a yttrium aluminium garnet (YAG) crystal, co-doped with Yb (10 at.%) and Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.35 mum and measured to be about 6% with respect to Yb3+ IR luminescence (lambda = 1.03 mum). Analysis of the crystal absorption and luminescence spectra allows one to conclude that Yb3+-Cr4+ energy transfer is a mechanism responsible for the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as an efficient source of the near infrared emission. (C) 2004 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Infrared (1.2-1.6 mu m) luminescence in a ytterbium aluminium garnet (YbAG) crystal, doped with Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.34 mu m and measured to be about 1.3 times with respect to Yb3+ IR luminescence (lambda = 1.03 mu m). We demonstrate that for the excitation wavelength of 940 nm Yb3+ ions act as sensitizers of the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as a high-efficient system for tunable laser (1.2-1.6 mu m) output. (c) 2004 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The 940 nm Al-free active region laser diodes and bars with a broad waveguide were designed and fabricated. The stuctures were grown by metal organic chemical vapour deposition. The devices show excellent performances. The maximum output power of 6.7 W in the 100 f^m broad-area laser diodes has been measured, and is 2. 5 times higher than that in the Al-containing active region laser diodes with a narrow waveguide and 1. 7 times higher than that in Al-free active region laser diodes with a narrow waveguide. The 19 % fill-factor laser diode bars emit 33 W, and they can operate at 15W with low degradation rates.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Contient : 1° La Somme des vices et des vertus [par Frère LAURENT] ; 2° « Moralitez des philosophes » ; 3° Sermon ; 4° Exhortation à l'amour de Dieu ; 5° « Ung petit Traictié faisant mencion du sacrement de l'autel et des biens qu il fait à ceulx qui en vraye foy et sans peché mortel le reçoivent » ; 6° « Comment l'en se doibt avoir durant le temps que l'en ot la messe » ; 7° Des Conditions du vrai religieux ; 8° Traité de l'amour divin ; 9° Des trois États de l'âme chrétienne ; 10° Traité de la crainte de Dieu ; 11° La Contemplation de Dieu

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

u.a. Naturwissenschaft; Schopenhauer Zitate; Wille als Ding an Sich; Mainbrücke in Frankfurt am Main; Erstes Treffen mit Schopenhauer; Buddhismus; Bibliothek;

Relevância:

20.00% 20.00%

Publicador: