Efficient and stable laser-driven white lighting

Kristin A Denault,Steven P Denbaars,Shuji Nakamura,Ram Seshadri,Michael Cantore

doi:10.1063/1.4813837

Abstract

Laser-based white lighting offers a viable option as an efficient and color-stable high-power solid-state white light source. We show that white light generation is possible using blue or near-UV laser diodes in combination with yellow-emitting cerium-substituted yttrium aluminum garnet (YAG:Ce) or a mixture of red-, green-, and blue-emitting phosphors. A variety of correlated color temperatures (CCT) are achieved, ranging from cool white light with a CCT of 4400 K using a blue laser diode to a warm white light with a CCT of 2700 K using a near-UV laser diode, with respective color rendering indices of 57 and 95. The luminous flux of these devices are measured to be 252 lm and 53 lm with luminous efficacies of 76 lm/W and 19 lm/W, respectively. An estimation of the maximum efficacy of a device comprising a blue laser diode in combination with YAG:Ce is calculated and the results are used to optimize the device.

Highlights

Laser-based white lighting offers a viable option as an efficient and color-stable high-power solid-state white light source
We show that white light generation is possible using blue or near-UV laser diodes in combination with yellow-emitting cerium-substituted yttrium aluminum garnet (YAG:Ce) or a mixture of red, green, and blue-emitting phosphors
We demonstrate that with current commercially available laser diodes and the appropriate mix of phosphors, high-power, efficient white light generation is achievable with good color rendition and in a variety of color temperatures

Summary

Introduction

Laser-based white lighting offers a viable option as an efficient and color-stable high-power solid-state white light source. We demonstrate that with current commercially available laser diodes and the appropriate mix of phosphors, high-power, efficient white light generation is achievable with good color rendition and in a variety of color temperatures.

Results

Conclusion