"Biophotonics" is a relatively new term that has a variety of uses. One applies to weak electromagnetic radiation emitted by living systems. Another applies to the use of such radiation to illuminate biological materials and in this way learn about them. The latter is a new name for a broad category of traditional research subjects in biophysics.
In the 1930s, Russian scientist Alexander Gurwitsch discovered that plants weakly emit light, called biophotons. He almost received the nobel prize for this discovery, but was passed over and the phenomenon was forgotten for some time.
In the 1970s, German biophycisist Fritz-Albert Popp rediscovered this property of living systems. Since that time, a number of teams worldwide have done research on the properties and function of biophotons.
Biophotonics has applications in food quality analysis, water quality analysis (ie. toxins) and disease analysis.
Biophotonics researchers regard their field as a holistic approach to understanding life and discuss questions of cognitive and science theory as well as the source of consciousness.