Competition between Raman and line-center oscillations in optically pumped far-infrared lasers

Abstract

Competition between Raman and line-center oscillations in off-resonantly pumped far-infrared lasers is studied by means of semiclassical laser theory. The observed preferential Raman line operation is shown to be caused by an inversion of the line-center gain when the Raman mode reaches intensities well below full saturation. This inversion is partly due to simple population effects. A further enhancement in the cross saturation at line center is caused by population pulsations. Numerical examples of mode competition are presented.