A dielectric wave guide (DWG) has a dielectric core member that has a first dielectric constant value. A cladding surrounding the dielectric core member has a second dielectric constant value that is lower than the first dielectric constant. A mating end of the DWG is configured for mating with a second DWG having a matching non-planar shaped mating end. A deformable material is disposed on the surface of the mating end of the DWG, such that when mated to a second DWG, the deformable material fills a gap region between the mating ends of the DWG and the second DWG.