Analysis of optically pumped compact laterally coupled distributed feedback lasers with three symmetric defect regions

This article analyzes compact laterally coupled distributed feedback (DFB) lasers with three defect regions. These devices are more flexible and smaller than conventional DFB lasers, having typical lengths between 20 and 50 μm and a width less than 1 μm (lateral gratings are inserted in a single-mode waveguide). We optimize the defect regions to achieve an improved performance. In other words, an adequate choice of phase shifts may lead to single-mode operation, lower threshold optical power, higher quantum differential efficiency, and more uniform field distribution. This device is designed to operate under optical pumping.