Theoretical Modeling of Relative Intensity Noise in p-Doped 1.3-μm InAs/GaAs Quantum Dot Lasers

Theoretical analysis of relative intensity noise (RIN) characteristics of p-doped QD lasers has been presented. By considering dynamics of electrons and holes separately at GaAs barrier, wetting layer (WL), and three discrete QDs levels, 12 rate equations have been linearized in presence of the Langevin noise sources. Calculations indicate that RIN level of QD laser reduces slightly through p-doping. Although providing excess holes to WL state decreases the shot noise, resulted from quantum confined levels and photon noise, the shot noise originated from three and two dimensional carrier densities, respectively, inside the barrier and WL states, increases. It is shown that the RIN level declines in p-doped QD lasers by increasing the injection current, which is in agreement with a recent experimental report. It is also demonstrated that the RIN level of QD lasers decreases by increasing the number of QD layers, and a shot noise plays the main role in this reduction.