Semiclassical theory of rectangular waveguide gas lasers

The semiclassical theory for gas lasers is extended from one dimension into three. Self-consistency equations of a rectangular waveguide resonator and the component equations of motion for the population matrix are derived. L aser parameters related to the waveguide structure and active medium are an alyzed by solving the equations, For homogeneously broadened lasers, theore tical investigation shows that single-mode operation depends on the wavegui de dimensions, the most probable speed of the active medium, and the decay constants or the saturation parameter. Under some conditions, the oscillati ng modes can be determined by the frequency interval and the relative excit ation.