Design and Development of Laser-Driven Multiple Phosphors Converted White Light Source in Concentric

Solid-state-lighting (SSL) is the current state-of-the-art technology for general-purpose illumination, high-tech display applications, and electronic devices [1]. In the era of SSL for artificial intelligence and robotic driving with a high brightness white light emitting diode (LED) could not survive due to its efficiency droop (ED) [2]. ED limits the generation of photons per unit area of LED by limiting input current densities. It’s very much predetermined for ultrahigh-brightness and high spatial resolution the most predicated solutions could be a laser diode which produces light like LED and operates much higher current and do not suffer from ED. In SSL the phosphor-converted laser diode (pc-LD) white light source, LD is focused onto the small area of phosphor for an ultra-high brightness illumination but the early thermal degradation and even in extreme cases phosphor resin burning appear. The most feasible approach for producing white light in pc-LD source is similar to pc-LED in which a blue LD is used to excite a down -conversion yellow phosphor
(Y 3 Al 5 O 12 : Ce) for generation of yellow photons. Further, the residual blue photons which are extracted from the phosphor layer due to scattering, combines with yellow photons to generate white light. But yellow phosphor possesses an optical spectrum that lack of deep red color
parameter (R 9 ~100%) and color rendering index (CRI) <60.To improve the quality of white light we introduce a significant amount of red and green emitter and removal of thermal heating used a rotating wheel. In this paper, we used three-color commercially available phosphor SrAlSiN 3 : Eu (627.0nm - Red), Y 3 Al 5 O 12 : Ce (555.0nm - Yellow) and SrBaSiO 3 : Eu (515.0nm - Green) combination for the experiment to design a sun like full spectrum (SFS) white light source with high thermal stability. We took a combination red and green with yellow in all possible configurations. High power blue LDs (λ=450.0nm Δλ=5.0nm P=1.5Watt) are aligned to illuminate rotating wheel attached with a 12V dc- motor, coated in novel concentric ring (width 5.0mm each) configuration pattern with green, yellow, and red phosphors. The rotating wheel system protects phosphor burning from direct exposer of high-power lasers as well as makes the illumination uniform. The proposed systems with inner ring of green middle one of yellow and outer most coated with red
phosphor has CRI 87 and the color temperature is 5572K cool white light with color coordinates very close to proper white light (0.33, 0.33). This work can be internally involved in illumination systems such as artificial solar simulator and headlamp.