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.