高均匀度LED植物光源的设计

针对现有植物灯均匀度差的问题，通过在R（红）、G（绿）、B（蓝）三色LED芯片上加装导光管和光纤透镜，实现了高均匀度的出光效果，通过调节导光管和光纤的尺寸获得了达90%的混色、光谱以及光量子通量密度（PPFD）的均匀性。进一步对光源的热学性能进行表征发现光纤透镜的增加有利于减少光源正面的热量，并且基于光量子学照明参数对该灯的均匀度进行评价，并进一步提出有效光能利用率来更加科学的表征光源性能。结果表明，混色均匀性与PPFD均匀性可达90%，有效光能利用率可达到43%。进一步将该灯用于鲜切玫瑰花保鲜，并通过脉冲宽度调制技术（PWM）实现了光谱的动态可调，通过对玫瑰花鲜重日失重率以及抗氧化物质如黄酮素等物质含量变化的测量，探究鲜切玫瑰花保鲜的最佳光照条件。实验结果表明，最有利于鲜切玫瑰保鲜的光质条件和光照周期为R+G、6 h/24 h。

Design of High Uniformity LED Plant Lamp

Aiming at the problem of poor uniformity of the existing plant lights, a high uniformity light was designed by installing light pipes and fiber lenses on R(red), G(green), and B(blue) three-color LED chips. By adjusting the size of the light pipe and the optical fiber, the uniformity of spectra, color mixing and photosynthetic photon flux density(PPFD) reached 90%. The thermal properties character of the light source were measured further. It was found that the increase of the fiber lens favored and reduced the heat at the front of the light source, and the uniformity of the lamp was evaluated based on the light quantum illumination parameters. Besides, effective light energy utilization was proposed to characterize light source performance more scientifically. The results show that the color uniformity and PPFD uniformity can reach 90%, and the effective light energy utilization can reach 43%. The lamp is further used for freshness preservation of fresh cut roses, pulse width modulation technology(PWM) is used to achieve dynamic adjustment of the spectrum, the weight loss rate of rose fresh weight and the content change of antioxidant substances such as flavone and other substances were investigated to explore the best light conditions for fresh-cut roses. The experimental results show that the light conditions and light duration that are most conducive to freshness preservation of fresh-cut roses are R+G and 6 h/24 h.