Experimental investigation on the nonlinear dynamical states of DFB semiconductor lasers subject to dual-beam optical injection

The nonlinear dynamic behaviors of the distributed feedback semiconductor laser (DFB-SLs) subject to dual-beam optical injection are experimentally investigated. The results show that the outputs of a DFB-SL subject to dual-beam optical injection display much rich and more complex nonlinear dynamical behaviors compared with that of a DFB-SL subject to single-beam injection. By fixing the oscillated wavelengths of two injection optical beams and continuously changing injection strengths of two injection optical beams, the output optical spectra and power spectra of the DFB-SL under different injection strengths of dual-beam optical injection have been measured. On the basis of the optical spectra and power spectra, some typical dynamical states have been determined under three cases categorized as scenarios A, B and C. Finally, we give the distribution map of the dynamical states of DFB-SL in the parameter space of two injection strengths, and the regions for scenarios A, B and C have been indicated.