Simple analysis of a diode laser having two orthogonal Fabry-Perot cavities

Simple rate equations have been used to analyze the steady-state behavior of a double-cavity diode laser with two separately driven active regions, one of which is shared by both cavities. It is shown that the output from one cavity depends with an inverse linear relationship on the output of the other, in agreement with the experimental results of Kosonocky, Cornely, and Marlowe. The stability of the steady-state solutions has been studied by a perturbation method, yielding a value for the response time of 0.2 ns. It is found that unstable situations exist for certain values of some of the parameters, indicating the possibility of an oscillatory output. A similar method of analysis has been used to obtain the response time of a normal single-cavity laser. For abrupt changes in the drive current when the laser is already emitting, the calculated response time is in good agreement with the experimental values obtained by Basov et al.