Influence of superluminescence on the gain in an active element utilizing organic compounds

The influence of superluminescence on the gain in an active element is analyzed using the quasisteady-state approximation. It is shown that total internal reflection in the active-element cell is a factor that severely limits the gain. In the presence of losses, the gain K initially increases with increasing cell length (at a constant pump power density), reaching a maximum, and then decreases, becoming K→0 for l → ∞. In the absence of losses, it is found that K→l.