Author:

Keywords:

Science & Technology, Physical Sciences, Optics, REMOTE PHOSPHOR, TEMPERATURE, PHOTOLUMINESCENCE, POWER, CE3+, 0205 Optical Physics, 0906 Electrical and Electronic Engineering, 1005 Communications Technologies, 4006 Communications engineering, 4009 Electronics, sensors and digital hardware, 5102 Atomic, molecular and optical physics

Abstract:

Multi-physics approaches are increasingly adopted in the development of efficient, high brightness solid-state light sources, in particular for the realistic modelling of the fluorescent colour conversion element that is typically used to create white light. When a fluorescent material is excited by a high-power laser diode, it will self-heat and reach high temperatures. The efficiency or quantum yield of fluorescent materials lowers as their temperature increases, an effect called thermal quenching. The lower efficiency further increases the amount of phosphor self-heating which can lead to thermal runaway. This effect has been considered by different researchers when modelling the opto-thermal behaviour of the fluorescent colour conversion elements. However, other key fluorescent properties such as the absorption and emission spectrum also depend on temperature, and often also on the radiant flux density. This gives rise to a complex set of interplays between optical and thermal properties which are not considered in the current opto-thermal models but that significantly influence the performance of fluorescent material based solid-state light sources. In this work, we present a holistic opto-thermal simulation framework: a novel comprehensive simulation tool that includes all relevant multi-physics considerations. We show that the framework allows for an accurate and realistic prediction of the performance of high-luminance solid-state white light sources by comparing simulation results to experimentalmeasurements of a laser-based configuration, thereby validating the framework.