enhanced modulation and noise characteristics in 1.55 µm qd lasers using additional optical pumping

the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to the qds' excited state through optical pumping, the bandwidth of laser increases. additional optical beam also helps qd laser to turn on during shorter delay time. further, it is deduced that rin level of qd laser reduces and the damping factor increases upon additional optical beam. moreover, the frequency noise level of qd laser and though its linewidth decreases in presence of additional beam. though, it is demonstrated that an additional optical pumping, improves the modulation response of qd laser besides lowering the level of its intensity and frequency noises.