RELAXATION OSCILLATIONS IN QUASI-SINGLE-MODE SEMICONDUCTOR-LASERS

The intensity-relaxation-oscillation (RO) and damping rates, and the l aser linewidth are measured and analyzed for a semiconductor laser und er quasi-single-mode conditions. The RO frequency and the laser-linewi dth dependence on laser power are measured, and are described well by the Henry single-mode theory. The relaxation-oscillation damping rate, however, shows a significant deviation from the expected power depend ence, and is found to depend on the effective number of idle modes, an d the fraction of energy in such modes. The observation is explained v ery well by a generalized quasi-single-mode theory that accounts for t he collective contribution of the idle modes.