The shape of the emission band of the -dopant in oxyfluoride nano-scaled glass-ceramics

¹ Departamento de Física Fundamental y Experimental, Electrónica y Sistemas Universidad de La Laguna - 38206 La Laguna, Tenerife, Spain
² Novel Photonic Glasses Research Group, Center for Advanced Materials University of Nottingham - Nottingham NG7 2RD, UK

Corresponding authors: vrguez@ull.es victor.tikhomirov@nottingham.ac.uk

Received: 30 July 2004
Accepted: 2 November 2004

Abstract

We propose a diagram showing the sequence of Stark-split energy levels for the and states of doped into oxyfluoride, nano-scaled glass-ceramics based on low- and room temperature measurements of respective emission and absorption bands. The room temperature broadest and flattest 1.55 telecommunications emission band of to date reported earlier for such glass-ceramics is interpreted using this framework. By investigating the low-temperature behaviour, we show that the shape of the 1.55 band at room temperature is mostly due to thermal population of higher Stark sublevels in the excited state. Two sites for are proposed which relate, respectively, to the glassy and nano-crystalline phases of the glass-ceramics and their relative contributions to the emission spectrum are identified. The -site in the nano-crystalline phase is shown to be cubic with nearby charge compensation by one interstitial , without appreciable clustering of ions.