A waveguide array can comprise a base portion having a metalized inner surface, an outer surface, and a clean end surface. The inner surface can include a plurality of waveguide channels that are metalized. The clean end surface can be prepared by breaking the base portion along a groove positioned on the outer surface prior to breaking, where the groove is oriented to intersect the waveguide channels. A metalized cover portion is attached to the inner surface of the base portion to close the waveguide channels.