Investigation of the relationships governing multimode excitation in injection lasers

The number of oscillation modes excited in all degrees of freedom in conventional and stripe GaAs and other lasers was determined for an excess over the threshold amounting to a factor of 3–5. The average output power per one excited mode was not more than 10 mW even when the total laser power reached tens of watts. The number of the longitudinal oscillation modes, governing the width of the spectrum, was in satisfactory agreement with calculations based on a spiking emission model. The influence of selective resonators, which could increase the single-mode output by a large factor, is discussed.