Vegetation has different absorption and reflection spectral characteristics in different bands. In visible
light band, chlorophyll has an absorption peak at the central wavelength of 0.45μm(blue) and 0.65μm(red), and a reflection peak near 0.54μm(green). In the mid-infrared phase of the spectrum, the spectral response of green plants is dominated by strong absorption bands of water around 1.4, 1.9 and 2.7 μm
The absorption rate of plants to red and blue color bands is relatively high, which is the main reason why plant growth lamps are mostly red and blue. But there is a misunderstanding. The amount of light a plant absorbs depends on the wavelength of the light itself, not its color. The so-called high absorption rate of
red and blue light refers to the natural color produced by the wavelength of
light, rather than the artificial addition of variable color light.
Laser plant growth light is red and blue because laser wavelengths are controlled, and visible light that mimics sunlight is red and blue in natural wavelengths. The red and blue colors of LED plant lights are caused by the light penetrating the tinted glass, or by chemicals that are discolored by the light. This is a light reaction of an element that reflects the color of the light reaction of a chemical element, rather than the natural wavelength of
light that corresponds to red and blue.
