  We introduce modeling and simulation of the noise properties associated with
types of modal oscillations induced by scaling the asymmetric gain suppression
(AGS) in multimode semiconductor lasers. The study is based on numerical
integration of a system of rate equations of 21-oscillating modes taking
account of the self- and cross-modal gain suppression mechanisms. AGS is varied
in terms of a pre-defined parameter, which is controlled by the linewidth
enhancement factor and differential gain. Basing on intensive simulation of the
mode dynamics, we present a mapping (AGS versus current) diagram of the
possible types of modal oscillations. When the laser oscillation is hopping
multimode oscillation (HMMO), the spectra of relative intensity noise (RIN) of
the total output and hopping modes are characterized by a sharp peak around the
relaxation oscillation (RO) frequency and a broad peak around the hopping
frequency. The levels of RIN in the regimes of single-mode oscillation (SMO)
are much lower than those under HMMO, and the mode-partition noise is two order
of magnitudes lower.
