Nonuniform distribution of gain along the cavity axis and lasing efficiency in a diode laser

Use is made of the analytical solution of the wave equation to simulate the light–current characteristics of Fabry – Perot diode lasers designed to operate at high powers. It is shown that at a high output power level, the presence of axial gain nonuniformity does not lead to deviations from the linearity of this characteristic. Only near the lasing threshold, a decrease in efficiency with pump current is found, associated with the transition from a uniform axial gain distribution to a self-consistent nonuniform distribution. It is found that with significant axial nonuniformity of the electron density that depends on the power level, the total optical length of the cavity remains constant.