Nonclassical light
In optics, nonclassical light is light that cannot be described using classical electromagnetism; its characteristics are described by the quantized electromagnetic field and quantum mechanics. The most common described forms of nonclassical light are the following: Photon statistics of nonclassical Light is sub-Poissonian in the sense that the average number of photons in a photodetection of this kind of light shows a standard deviation that is less than the mean number of the photons.