Two-photon physics definition
Two-photon physics (also known as double-gamma physics) is a branch of particle physics that describes the interaction between two photons. Generally speaking, the beam will not be disturbed when it crosses. In some specific optical materials, if the intensity of the beam is high enough, then these beams can affect each other through a series of nonlinear effects. In a pure vacuum environment, if the center-of-mass energy of the dual photosystem is large enough, weak light scattering caused by light will occur. In addition, if the energy is higher than a certain threshold, part of the energy will be converted into new substances.