A luminaire reflector comprises a first end reflector segment, a second end reflector segment, and a main reflector segment bonded together as a single-piece. The main reflector segment, the first end reflector segment, and the second end reflector segment form a microwave cavity that can accommodate a microwave-powered bulb. The luminaire reflector is configured to be mated to at least one waveguide of a luminaire assembly. The luminaire reflector comprises at least one RF coupling slot to transmit microwave energy from the waveguide side to the microwave cavity side of the reflector assembly.