" Scientists have long known that the chlorophyll in most plants on Earth absorbs blue and red light and less green light. Therefore, chlorophyll appears green. Although some green color is absorbed, it is less than the other colors.
Previously, scientists thought plants are not efficient as they could be, because they do not use more green light.
According to scientists, the Sun has a specific distribution of colors of light, emitting more of some colors than others. Gases in Earth's air also filter sunlight, absorbing different colors.
As a result, more red light particles reach Earth's surface than blue or green light particles, so plants use red light for photosynthesis. There is plenty of light for land plants, so they do not need to use extra green light. But not all stars have the same distribution of light colors as our Sun. Study scientists say they now realize that photosynthesis on extrasolar planets will not necessarily look the same as on Earth. "
http://www.nasa.gov/centers/goddard/news/topstory/2007/spectrum_plants.html
In a grow tent/room there's never plenty of light ...
Not like the Sun's ....
Leds surely ,do not imitate natural sunlight ...
Still white leds (specially combined with red leds 620-660 nm ) ,
can provide a 'rich ' light ,that plants can take advantage of every single nanometer ...
Red alone ,would not help in growing healthy ,productive plants ...
Combined with blue ,things get much better ...
'Throwing' the rest of the wls ,things get even better ....
Now ...To make life easier for a led grow light designer ...
Wouldn't be a great thing ,to have to 'deal' with just one type of led emitter ,that can
provide plenty of Red wls ,along with all the rest ?
Not being obligated ,to install and place different types of monos ?
An emitter that is (almost) as efficient as most of the red leds ?
Well ,that emitter already exists ....
In fact it is not just one ...
You 've CXA's & Vero's ,for starters ...
Soon,others will follow along ,I guess ..
