Over 12 years of research has shown that the Pulsed Alternating Wavelengths System (PAWS), is the most effective way of delivering light to plants and animals. PAWS technology takes advantage of proteins present in both plants and animals called chromophores. Chromophores are proteins that change their shape in response to light energy. This conformational change results in a subsequent biological change in the plant or animal.
There are thousands of different chromophores and most of them are "bi-phasic", meaning they exist in two distinct states. One state is when they are in a "ready" state and can accept a light photon of a specific wavelength. After receiving a light photon, the chromophore undergoes a conformational change and sends off a signal, activates a receptor, opens a ion channel, etc. At this point the chromophore is in a "refractory" state and can no longer accept the initial photon wavelength.
In order for a chromophore in a refractory state to "reset" to its ready state typically requires a multi-step chemical pathway that takes time. During this time, the chromophore in its refractory state cannot perform its intended "job". The second pulse of light in PAWS is a different wavelength and gives the chromophore the energy to immediately return to its "ready" state. This shortening of the refractory period of the chromophore allows more light initiated information signaling to be driven to the organism.
These chromophore changes are photo-chemical reactions that happen in the order of femtoseconds. It is not necessary to deliver light to plants or animals with on off-cycles that mimic the sun (24 hrs). Instead, these pulsed light signals can be given as a function of ratios of near-red, far-red and blue wavelengths thousands of times per second. This ability to control signaling is what drives day length and seasonality information to the organism.