Nonlinear dynamics in directly modulated multiple quantum well laser diodes

An analysis of the nonlinear dynamics of Fabry-Perot and distributed feedback multiple quantum well laser diodes is presented. The analysis is performed under single-tone and two-tone direct modulation. In the Fabry-Perot laser we observe period doubling and in the distributed feedback laser both period doubling and period tripling are identified. Period doubling is found over a wide range of modulation frequencies in both lasers. The reason for this wide modulation frequency range is attributed to the large relaxation frequencies found in multiple quantum well laser diodes. The dependencies of period doubling on bias current and RF input power level are also analysed. The nonlinear dynamics of the laser are found to be enhanced when modulated under two-tone modulation