Output power of a ridge semiconductor laser in the single-frequency regime

It is shown that the single-frequency output power of a semiconductor laser with a built-in horizontal waveguide and typical parameters is restricted from above. This restriction is caused by a change in the effective gain for longitudinal modes adjacent to the laser mode due to a nonlinear process producing oscillations of the carrier concentration at the intermode frequencies. If the laser resonator contains random or deliberately introduced inhomogeneities, the maximum achievable single-frequency output power can considerably (more than by an order of magnitude) exceed the output power in the absence of inhomogeneities.