Aquino Felipe, Jadwisienczak Wojciech M, Rahman Faiz
Appl Opt. 2017 Jan 10;56(2):278-283. doi: 10.1364/AO.56.000278.
Laser diode (LD) pumped white light sources are being developed as an alternative to light-emitting diode-pumped sources for high efficiency and/or high brightness applications. While several performance metrics of laser-pumped phosphor-converted light sources have been investigated, the effect of laser speckle has not been sufficiently explored. This paper describes our experimental studies on how laser speckle affects the behavior of light from laser-excited phosphor lamps. A single LD pumping a phosphor plate was the geometry explored in this work. Overall, our findings are that the down-converted light did not exhibit any speckle, whereas speckle was present in the residual pump light but much reduced from that in direct laser light. Furthermore, a thicker coating of small-grained phosphors served to effectively reduce speckle through static pump light diffusion in the phosphor coating. Our investigations showed that speckle is not of concern in illumination from LD-pumped phosphor-converted light sources.
激光二极管（LD）泵浦白光源正在被开发，作为用于高效率和/或高亮度应用的发光二极管泵浦光源的替代品。虽然已经研究了激光泵浦磷光转换光源的几个性能指标，但激光散斑的影响尚未得到充分探索。本文描述了我们关于激光散斑如何影响激光激发磷光体灯发出的光的行为的实验研究。单个LD泵浦磷光板是本工作中探索的几何结构。总体而言，我们的发现是，下转换光没有显示出任何散斑，而残余泵浦光中存在散斑，但比直接激光中的散斑大大减少。此外，较厚的小颗粒磷光体涂层通过磷光体涂层中的静态泵浦光扩散有效地减少了散斑。我们的研究表明，散斑在LD泵浦磷光转换光源的照明中不是问题。
