Cooperative luminescence as a probe of clustering in Yb3+ doped glasses

An emission centred around 500 nm under near infrared excitation has been o bserved in Yb3+ doped borosilicate, aluminosilicate and phosphate glasses. Lifetime measurements and convolution of infrared luminescence spectra conf irm the cooperative nature of this visible emission. Cooperative luminescen ce intensity, i.e. rare earth clustering, strongly depends on the glass com position studied. In the phosphate glasses, a good correlation is found bet ween the structural evolution of the glass and the cooperative emission int ensity. (C) 2000 Elsevier Science S.A. All rights reserved.