Photonic wire lasers are compact light sources that are fabricated in high-index contrast waveguides (with typical widths of a few hundreds of nanometers). Because of their small footprints, they may become a basic laser component in future - generation of optical integrated circuits. Owing to having low optical volume by design, photonic wire lasers can only produce low output power that may not be adequate in many applications. A solution to this problem is to coherently combine the output power of different photonic wire lasers to produce larger output power. In this article, we analyze different ways to combine light coming out from photonic wire lasers and couple the combined power into a single-mode waveguide.