Laser-Driven White Light Source With High Luminescence Saturation Through Reflective Color Converter

In this letter, a laser-driven white light source with high luminescence saturation was fabricated by combining blue laser chips and an Al2O3-doped reflective color converter. The reflective converter was prepared by printing and sintering an Al2O3-doped phosphor-in-glass (PiG)film on an AlN substrate. The Al2O3-PiG film with intactcrystal structure of YAG phosphor is robustly bonded on the substrate. The optical and thermal performances ofAl(2)O(3)-PiG based phosphor-converted white laser diodes(pc-WLDs) were optimized with different Al(2)O(3)contents.The pc-WLD achieves a maximum saturation threshold of25.2 W/mm(2)and a high luminous flux of 2138 lm (luminance of 1260 Mcdm(-2)). The working temperature of 6%-Al2O3-PiG is only 88.4(degrees)C, which is reduced by 33.5% compared with that of Al2O3-free-PiG. The fabricated small pc-WLD device has high-luminance white light, excellent collimation, and long illumination distance, which is a promising light source for high-brightness lighting.