Abstract: The applications of numerical simulation in ＂the principle of lasers＂ are discussed. The progress from pumping, relaxation oscillation, gain saturation to steady output of the three-level system lasers is posted by numerical solution of the rate equations based on ruby lasers. The procession of self-reproducing mode formation is demonstrated based on diffraction theory and Fox-Li iterative method. Numerical simulation makes abstract theoretical equations to be concrete, which helps students understand basic concept and increases the ability of solving practice problem for the students.

Key words: principle of lasers, numerical simulation, rate equations, self-reproducing mode