High luminous fluorescence generation using Ce:YAG transparent ceramic excited by blue laser diode

Solid-state laser lighting is an emerging technology, whereby high-brightness white light can be generated using blue laser diodes combined with a yellow-emitting phosphor. In this study, Ce:YAG transparent ceramic wafers with different cerium concentrations and thicknesses are prepared and their optical characteristics are measured. A transmission mode is used, wherein the phosphor ceramic is fixed onto an oxygen-free copper sink, whose temperature is accurately controlled, and excited using the blue laser diode. The recorded spectrum shows that blue laser light is completely converted to yellow light with a wavelength of 565 nm and width of 200 nm. Moreover, with varied temperatures of 10-80 °C, the luminous flux, spectrum, and color coordinates exhibit relatively stable. More importantly, the luminous flux is highest (2690 lm) when irradiated by a 19.5-W blue laser (with a center wavelength of 454 nm) for a Ce³⁺ dopant concentration of 0.5 mol% and a Ce:YAG thickness of 1.6 mm. Based on these results, the Ce:YAG transparent ceramic can be used as a potential phosphor material in applications of high-power solid-state laser lighting and laser display. © 2018 Optical Society of America.