White-light sources based on GaN laser diodes: analysis and application study

We report on the design and study of solid state laser sources for lighting applications. While LEDs are affected by droop, limiting efficacy at higher currents, a possible solution is represented by solid state laser lighting, where a blue (450nm) laser is exciting a luminescent material thus achieving white light. With this work we designed and tested several LARP (Laser-Activated-Remote-Phosphors) test structures, both diffused lighting and focused applications will be discussed. Results indicates that good efficiency are achievable, without any sensible droop also at high injection currents. Phosphors have also been subjected to thermal stability tests up to 550°C.