Luminescence saturation studies of YAG: Ce phosphor ceramics for white laser diode lighting

As a new generation of solid-state lighting devices, phosphor-converted white laser diodes are required to be able to reach high-power. For white laser diode lighting, high-power laser excitation is necessary to obtain high luminous flux. Here, the change of luminous flux of YAG: Ce phosphor ceramics excited by the high-power blue laser is systematically investigated by regulating the blue laser power, irradiation distance, and irradiation time. The results indicate that the luminous flux is basically unchanged when the change in the irradiation distance is less than 10 cm. Moreover, when the blue laser power changes from 3.01 to 19.21 W, the luminous flux is increased by 285%. The saturation thresholds of YAG: Ce phosphor ceramics exceed 27 W. The results show that the collimated laser beam excision can significantly reduce the effect of spot area on the luminous flux, and significantly enhance the saturation laser power of the YAG: Ce phosphor ceramics.