Abstract

Quantum dot (QD) lasers are promising devices because of significant improvements in modulation bandwidth, lasing threshold, relative intensity noise, linewidth enhancement factor, and temperature insensitivity. The rate equation modeling of the response of QD lasers is, however, challenging because of the large variety of QD lasers currently designed and the lack of systematic comparisons between theory and experiments. A minimal description that takes into account the carrier capture process and Pauli blocking is provided by three rate equations that permit analytical studies but still need to be tested experimentally [1]. On the other hand, a five-variable rate equation model that incorporates microscopic kinetic equations has led to an excellent quantitative comparison between experiments and theory for single turn-on experiments [2]. However, the complexity of this model limits direct analytical studies. This has motivated the present detailed asymptotic analysis. We show that the 5-variable rate equation model can be reduced to an effective 2-variable system, which permits to clarify the relevant dynamical processes during the laser turn-on. Our objective is to determine practical analytical expressions for (i) the steady state intensity, (ii) the relaxation oscillation frequency, and (iii) the damping rate which could be guidelines for optimizing the performances of QD lasers.

© 2009 IEEE