Illumination uniformity of an LD and LED hybrid lighting system applied to plant growth.

To develop a current plant lighting source with both a suitable illumination area and high illumination uniformity, we propose a lighting system for plant growth based on the combination of laser diode and LED lighting modes. We added a triangular-prism-shaped base plate element to the previous array type optical structure to increase the light coupling degree and expand the illumination area. The Taguchi method was used in our design and experiment, and the influence of different factors on the illumination uniformity was studied and compared to the lighting effect of a traditional array floor structure. Finally, a plant lighting source with an illumination uniformity of 88.54% and color-mixing uniformity of 84.75% was obtained. Compared to the commonly adopted array structure, this plant lighting source expands the illumination area by 31.03%, which verifies the effectiveness of the scheme.