Near infrared to red and yellow to blue upconversion emissions from Pr3+:: ZrF4-BaF2-LaF3-YF3-AlF3-NaF glasses

This paper describes the development and a detailed analysis carried out on the luminescence characteristics of Pr3+ doped ZrF4-BaF2-LaF3-YF3-AlF3-NaF glasses. In the present work our objectives are to elucidate the possible mechanisms that are responsible for NIR to red upconversion process and yellow to blue upconversion emission in terms of energy level schemes from the praseodymium containing fibre optical glass composition. We have studied their different physical and optical properties. Besides our investigation on the upconversion emission of these glasses, normal fluorescence studies have also been undertaken in explaining the mechanisms in demonstrating bright red and blue emissions upon excitations at visible and UV wavelengths. Besides these measurements works, a bright blue colour emission was observed under an UV source (202 nm) and upconverted prominent red emissions were observed with a laser diode (LD of 980 nm). Similarly under a yellow light source, a blue colour emission was observed from these prascodymium glasses studied. (C) 2003 Elsevier Ltd. All rights reserved.