Abstract
Influence of the nonlinear gain (NLG) and nonradiative recombination life time ratio (NRRLTR) on the rout to chaos and noise characteristics of semiconductor lasers (SLs) subject to optical feedback (OFB) are investigated. The analyses are performed in terms of the temporal trajectory of the photon numbers, bifurcation diagrams and relative intensity noise (RIN). Variations of the fluctuations of the photon number are statistically analyzed. The corresponding frequency dependence of RIN is characterized. The simulation results show that, NLG and NRRLTR can cause significant changes in the rout to chaos of the SLs and probability distribution of the photon numbers. We found that the value of the OFB rate at which the transition from CW to periodic oscillation (PO) or chaos state occur increases, as the value of the NLG/NRRLTR is increased/decreased. The RIN is found to be suppressed when the laser is operated in CW or PO region and at relatively higher/lower values of the NLG/NRRLTR. We believe that, the instability of the SLs can be reduced by operating it under OFB and by increasing/decreasing the values of the NLG/NRRLTR parameter.