Trapped whispering-gallery optical modes in white light-emitting diode lamps with remote phosphor
Open Access
- 24 July 2006
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 89 (4), 041125
- https://doi.org/10.1063/1.2221747
Abstract
Three-dimensional ray tracing simulations show that a significant fraction of the phosphorescence emitted in high-power white light-emitting diode lamps with a remote phosphor is trapped as whispering-gallery modes propagating along the circumference of the encapsulant. The whispering-gallery modes, which are a significant optical loss mechanism and occur for multiple shapes of the encapsulation dome, are shown to be sensitively dependent on the diffusivity of the reflector cup employed in the lamp. By employing a diffuse reflector cup, up to 86% of the trapped modes is extracted out from the encapsulant. In addition, it is experimentally demonstrated that the phosphorescence efficiency is improved by up to 12.2% as the diffusivity of the reflector increases. The experimental results are consistent with theoretical ray tracing simulations.Keywords
This publication has 8 references indexed in Scilit:
- Analysis of high-power packages for phosphor-based white-light-emitting diodesApplied Physics Letters, 2005
- Strongly Enhanced Phosphor Efficiency in GaInN White Light-Emitting Diodes Using Remote Phosphor Configuration and Diffuse Reflector CupJapanese Journal of Applied Physics, 2005
- GaInN light-emitting diodes with RuO2/SiO2/Ag omni-directional reflectorApplied Physics Letters, 2004
- High Power LEDs - Technology Status and Market Applicationsphysica status solidi (a), 2002
- Illumination with solid state lighting technologyIEEE Journal of Selected Topics in Quantum Electronics, 2002
- Luminescence conversion of blue light emitting diodesApplied Physics A, 1997
- Whispering-gallery mode microdisk lasersApplied Physics Letters, 1992
- Mie scattering and rough surfacesApplied Optics, 1985