Dehydroxylation processing and lasing properties of a Nd alumino-phosphate glass.

• Water content in the glasses is intimately related to the melt viscosity. • Temperature and time of dehydroxylation has been optimized for the title glass. • The method of dehydroxylation has shown to be efficient for up to 50 g of glass. • The Nd 2 O 3 doped glass showed excellent optical characteristics and laser performance. • Nd3+ ions may be present in two structural environments within the glass matrix. A photograph of an as-melted dehydroxylated Nd 2 O 3 doped laser phosphate glass where inset shows the time-evolution of stimulated emission pulses at pump energies of 28 mJ and 45 mJ and pump pulse at 802 nm wavelength. [Display omitted] In this work, we have studied the preparation and properties of an alumino-phosphate glass with composition 13Na 2 O-13K 2 O-16BaO-4Al 2 O 3 -54P 2 O 5 (mol%). The first part of the work deals with the study of the processing conditions of the dehydroxylation of the phosphate glass, which was performed by remelting under N 2 flow using graphite crucibles. Glass samples from 5 to 50 g and Nd 2 O 3 doped were submitted to dehydroxylation and the influence of temperature, time, mass of glass and viscosity were correlated with the content of water in the glasses through the coefficient of absorption of OH ions. The network structure of the glasses was also determined by means of 31P and 27Al 1D/2D nuclear magnetic resonance and the local environment of Nd3+ ions was probed by electron paramagnetic resonance. The optimized conditions of processing were then used to obtain a dehydroxylated glass with a 2.5 wt% Nd 2 O 3 whose spectroscopic and laser emission properties were studied. The spectroscopic properties of Nd3+ ions which include, Judd-Ofelt calculation, stimulated emission cross-section of the laser transition, lifetime, and quantum efficiency are presented. Site-selective laser spectroscopy and stimulated emission obtained under selective wavelength pumping along the 4I 9/2 →4F 5/2 absorption band were performed to determine the distribution of crystal field in which the rare earth is located, together with its influence in the pump wavelength dependence of the spontaneous and laser emissions of Nd3+ in this glass matrix. [ABSTRACT FROM AUTHOR]