A novel AlN based dual color spliced color wheel enabling high power density Laser projection

Laser projection faces the challenge of developing color converters with efficient thermal dissipation and superior luminous quality. This study developed a LaSi 6 N 11 :Ce 3 + (LSN) phosphor-in-glass film (PiF) on aluminum nitride (AlN) color wheel (LSN-CW). The fabricated dynamic converter preserves the optical properties of the phosphor, sustaining laser power density up to 40 W/mm 2 and luminous flux (LF) of 4188.1 lm without light saturation - exceeding the maximum LF of 817.1 lm for static converter LSN PiF on AlN (LSN-PiF) by over fivefold. Notably, under 40 W/mm 2 laser excitation, the operating surface temperature of LSN-CW remains as low as 344.9 K, significantly preserving the phosphor’s luminous performance. Furthermore， by incorporating CaAlSiN 3 :Eu 2+ (CASN) red spectral components, we successfully constructed an AlN based dual color spliced color wheel. The resulting device achieves balanced luminous performance and high quality color output, generating LF of 2656.8 lm and warm white light with a high color rendering index (CRI) of 88.3. This discovery could significantly advance the development of laser projection. • Static converter LSN-PiF exhibits high thermal conductivity (≈ 64.1 W·m -1 ·K -1 ) and can produce a maximum LF of 817.1 lm and maximum LE of 126.1 lm/W under 7.1 W/mm 2 . • Under a power density of 40 W/mm 2 , the dynamic converter LSN-CW device maintains a surface temperature of merely 344.9 K while achieving a LF output of 4188.1 lm with a maximum LE of 126.4 lm/W without optical saturation. • The prepared dual-color segmented color wheel combines high LF and excellent color quality, enabling high-quality white laser projection with finely adjustable color output ranging from cool white to warm white.