A reflective sapphire@PiGF@alumina color converter enabling ultrahigh luminescence laser-driven white lighting

High-brightness laser lighting faces grave challenges in developing laser-driven color converters with simultaneously possessing excellent optical performance and superior heat dissipation. Herein, a reflective sandwich color converter of phosphor‐in‐glass film with sapphire and alumina (sapphire@PiGF@alumina, abbreviated as S@PiGF@A) is designed and prepared by a thermocompression bonding method. Benefiting from the high thermal conductivity and double-sided heat dissipation channels of alumina and sapphire, the S@PiGF@A color converter can withstand high laser power density and produce ultra-high luminescence. Consequently, the optimized S@PiGF@A converter yields white light with an ultrahigh luminous flux of 6749 lm at a laser power density saturation threshold of 47.70W/mm², which is 2.44 times that of traditional PiGF@alumina color converter (2522 lm@19.53 W/mm²). The findings provide valuable guidelines to design high quality PiGF color converter for high brightness laser-driven white lighting.