Application of the geometrically dependent gain coefficient model to describe amplified spontaneous emission behavior in organic solid laser materials: theoretical considerations

摘要

A model of geometrically dependent gain coefficient is applied to small-sized media to explain the amplified spontaneous emission intensity and bandwidth reduction along the light propagation direction. The model is used for two typical experimental examples of photo-pumped pyrromethene 567-doped polymer and BuEH-PPV conjugated polymer wave-guides, and excellent consistency with the measurements is obtained. The calculations are performed both analytically and numerically, where the effect of saturation on the gain coefficient for the homogeneously broadened line-shape upon using a 4-level system is considered.