Highly heat-dissipating phosphor-in-glass film converter for high‐luminance laser lighting

A new phosphor-in-glass film (PiGF) color converter with high heat dissipation capability was proposed for high-power laser illumination. To intensify heat conduction, a composite structure was fabricated by welding the PiGF to a copper block through a silver layer. The PiGF converter was found to have a high quantum yield and similar fluorescence lifetime as the original phosphors. The optical characteristics of this material were investigated by varying the thickness of PiGF and the lase power. Under the excitation of 8.78W laser power, the PiGF converter with 100 μm film thickness enables a luminous efficacy of 187.9 lm/W, a CCT of 6150 K, and a perfect chromaticity coordinate of (0.3174, 0.3351). In addition, a maximum luminous flux of 4449 lm was obtained when the laser power reached 27.42 W. Besides, The PiGF converter displayed low working temperature and stable optical performance under the sustained excitation test, which indicates that the PiGF converter exhibits excellent opto-thermal performances. In general, an effective solution is put forward for the heat dissipating obstacle of laser lighting.