Symmetry Violation of Time Reversal in Light’s High Order Nonlinear Stimulated Radiation and Absorption Processes

The stimulated stimulated radiation and absorption theory of light based on low order linear interaction is considered symmetrical in time reversal processes at present. It is provided in the paper that after high order nonlinear interaction between radiation fields and charged particles is considered, time reversal symmetry in the stimulated radiation and absorption processes would be violated. Two reasons lead to symmetry violations of time reversal. One is the difference of initial states before and after time reversals. Another is the asymmetry of interaction Hamiltonian under time reversal. For single photon’s stimulated radiation and absorption in unite time, symmetry violation caused by initial state’s differences takes place in the second order processes. Symmetry violation caused by the asymmetry of interaction Hamiltonian takes place in the third order processes. The results means that even though the interaction Hamiltonian is unchanged under time reversal, the difference of initial states would also violate time reversal symmetry and the difference of initial states plays a more important role than asymmetry of interaction Hamiltonian in light’ stimulated radiation and absorptiom processes. In this way, the parameters of stimulated radiation and absorption are different with Bik 6= Bki. Based on revised theory, the non-equilibrium and nonlinear phenomena just as generation of laser, amplification of non-population inversion, self-induced transparency and self-induced absorption can be explained more rationally. Other nonlinear processes such as light’s multiple frequency, sum frequency and difference frequency, double stationary state, self-focusing and self-defocusing, double and multi-photon absorption, stimulated Raman and Brillouim scatterings, photon echo and so on are also enumerated and analyzed in the paper. The results show that most processes of nonlinear optics are violated time reversal symmetry obviously. PACS numbers: 42.55A,42.65,T,11.30.Q In order to provider a theoretical explanation for the Planck blackbody radiation formula, Einstein put forward stimulated radiation and absorption theory of light in 1917. According to the theory, there are three kinds of transitions, i.e., spontaneous radiation, stimulated radiation and stimulated absorption. Suppose the system haveN = N1+N2 particles in unite volume and two energy levers, E1 is low energy lever and E2 is higher energy lever with E2 > E1. N1 particles are in low energy lever and N2 are in high energy lever. Let ρ(v) represents the energy density of rediation fields, A21 represent spontaneous radiation probability of a particle in unite time, B12 represent stimulated absorption probability of a particle in unite time by unite radiation density andB21 represent stimulated radiation probability of a particle in unite time caused by unite radiation density. There exist so-called detailed balance when the system is in a stationary state with B12N1ρ(ν) = A21N2 +B21N2ρ(ν) (1) If the system is in thermal equilibrium, the particle’s population in different energy levers satisfies the Boltzmann distribution. Then suppose B12 = B21 A21 = h̄ω c3π2 B21 (2)