Infrared and visible room temperature fluorescence induced by continuous laser excitation of new Nd3+: phosphate glasses

A new family of transparent phosphate glasses having compositions 60% P2O5. 13% ZnO, 5%Al2O3, 22%(La2O3+Nd2O3) (wt%), slightly violet coloured have be en synthesised, using a regular melting technique to obtain new optical lum inescent hosts and eventually giving laser effect particularly at 1300 nm. IR fluorescence spectra investigation under different laser excitations at room temperature and 77 K show three major emissions situated at 1050, 1067 , 1082 nm. The variation of F-4(3/2) --> I-4(11/2) band width from 25.4 to 28.4 nm with the excitation change, demonstrates the crystal field inhomoge neity around the cation sites, whereas the (F-4(3/2) --> I-4(13/2)) is not affected and I-peak(F-4(3/2) --> I-4(11/2))/I-peak (F-4(3/2) --> I-4(13/2)) was similar to 7. The intensities of visible luminescence spectra are conc entration dependent under the 514.5 nm continuous laser excitation. A radia tive decay time is calculated on the basis of the Judd-Ofelt theory. (C) 19 99 Elsevier Science B.V. All rights reserved.