Analysis of lateral-mode behavior of twin-stripe lasers related to the negative slope in their current-light characteristics

The lateral oscillation mode in twin-stripe lasers is analysed with the diffusion constant D in the active layer as a parameter. Characteristics of modal gain and optical intensity distribution vs. current are shown to be strongly dependent on the diffusion constant because the diffusion constant determines the depth of the dip in the carrier distribution. For certain values of D, results which are in good agreement with experimentally observed results were obtained. A negative slope appears in the curves of modal gain vs. current, and the optical field is in the weakly pumped side in the negative slope region. The condition for which the negative slope appears is determined.<>