Bragg soliton in a periodic resonance structure with arbitrary resonant atom concentration profile

Nonlinear interaction between the intense coherent optical radiation and the continuous resonant photonic crystal with an even function of the resonant atom concentration distribution is numerically and analytically investigated within the framework of semi-classical approach using the two-wave Maxwell–Bloch equations. An analytical solution is found, which represents a Bragg soliton of self-induced transparency. By the specific example of the photonic crystal with the resonant atom concentration that changes according to the cube law a good agreement between analytical and numerical results is obtained.