The characteristics of ultrashort laser pulses propagation in cylindrical symmetry resonance media

Abstract：The spatial effect of ultrashort pulse laser propagating through cylindrical symmetry resonance media was discussed by simultaneously solving the Maxwell-Bloch equations with definite differential method. Two problems were solved in numerical calculation, one was that a term of 1/r in Maxwell was divergence in cylindrical center where r=0, another was that the value of optical field at cylindrical center was difficult to decided when the cylindrical center set as a boundary condition in Maxwell equation, So the values of optical field need just calculate from cylindrical center to cylindrical boundary, comparing from cylindrical boundary to cylindrical boundary, near upon half CPU time and RAM saved. Results indicate that the propagating of a 2 pulse form would no longer be a soliton when spatial effect was taken into account, its profile would distort, and the degree of distortion depends on the interaction intensity of laser and material: the stronger interaction, the more distortion till the profile split. The interaction intensity was decided by such elements as laser intensity, the dipole of material, and the concentration of resonance particles.