Differential quantum efficiency of a h omogeneously broadened injection laser

The differential quantum efficiency (DQE) of a two-level homogeneously broadened injection laser is studied. It is shown that a simple analytic expression for the DQE provides an accurate approximation to the actual DQE over a wide range of parameters, and that this simple expression can be used to scale the output of an analytic model which assumes alpha = 0 to predict accurately the output of a laser for alpha is not equal to 0. The parameter alpha is a nonsaturating loss which decreases the DQE of the laser from unity. The results of this paper show that it is possible to extend the range of validity of the alpha = 0 analytic model to regions where numerical analyses were only previously available.