In this paper, some of the activities towards the fabrication of Photonic Integrated Circuits at the COBRA Research Institute are summarized. Firstly, rate equations are used for the understanding of instability and dynamics in multilongitudinal mode semiconductor lasers. Secondly, we report the results of our investigation on broad-bandwidth frequency comb generators based on novel mode-locked InAs/InGaAsP/InP quantum dot laser diodes. In addition, we will show the integration of two-dimensional pillar-based photonic crystal waveguides in an InGaAsP/InP photonic integrated circuit. © 2008 IEEE.