Modulated Electoromagnetic Waves in Nonlinear Dispersive Media

抄録

The full description of modulated electromagnetic waves in a dispersive medium with cubic nonlinearity is derived with the use of the concept of quasi-particle. The conservation laws of occupation number (action), phase, energy and momentum of quasi-particle (modulated wave) are derived. An equilibrium state in a gas of quasi-particle is shown from the conservation law of occupation number. With the use of a generalized basic equation, a solitary wave (soliton) and the two types of instabilities in two-wave interaction are discussed. If the two-wave interaction is negatively (positively) dissipative, the instability of each wave is enhanced (quenched) with each other.