Far-field studies on Eu3+-doped lithium aluminoborate glass for LED lighting

Abstract

The luminous intensity distribution from luminescent glass disks is investigated. For this, the disks are placed on top of an ultraviolet and a blue LED and the emission from the optically-activated glass is recorded in the far field. The luminous intensity distribution of the LED light and the Eu3+luminescence is considered separately by filtering the LED excitation, the same applies to the measured total luminous flux. Angle-dependent spectra are also measured and the changes in color coordinates are examined versus the viewing angle. The experimental results of the luminous intensity distribution curves are compared with ray-tracing simulations. Keywords: Borate glass, Lanthanide doping, Luminous intensity distribution