The impact of laser speckle on color spatial uniformity in laser-excited phosphor-converted white light systems

This study delved into the impact mechanisms of laser speckles on the quality of phosphor-converted white light, employing both simulation and experimental approaches. We comprehensively analyzed and assessed the interactions between laser speckle contrast, phosphor concentration, and color spatial uniformity in laser-excited phosphor-converted white light. Our findings indicate that while laser speckle does not shift the overall average color temperature, it significantly affects the spatial distribution of color within the emitted white light. Consequently, setting appropriate upper limits for laser speckle contrast, tailored to specific phosphor concentrations and lighting scenarios, is essential for engineering high-quality laser-excited phosphor white light. This research provides valuable data and practical guidelines for designing laser-excited phosphor illumination systems to optimize color spatial uniformity.