Two-mode optical pumping of a laser

The coherent optical pumping of a laser is investigated by means of semiclassical laser theory with the assumption that either the pump source or the laser output is multimode. All radiation modes are allowed to reach saturating levels. A multitude of interesting effects result from induced population pulsations. As a particular application we study numerically the optical pumping of a single-mode homogeneously broadened FIR laser with a two-mode pump. We find that at least for symmetric pumping higher FIR intensities can be obtained with two, instead of one, pump modes.