High brightness laser-driven white emitter for Etendue-limited applications.

Laser-phosphor lighting has great potential because a laser diode (LD) could keep high efficiency under high current. Remote phosphor configuration has been studied, but a phosphor-covered LD has not been reported due to several difficulties. In the present work, we develop a novel laser-driven white emitter. Without remote phosphor configuration, the white emitter has a very simple structure, making it is easy for mass production and standardization. Under a continuous wave driving current of 3 A, it emits 850 lm with correlated color temperature of 6990 K. The wall-plug efficacy is 70 lm/W for the maximum. The laser-driven white emitter is very suitable for Etendue-limited applications due to its very small emitting size of 0.45  mm×0.2  mm.