Systems and methods in accordance with embodiments of the invention generate tunable electromagnetic waves using carbon nanotube-based field emitters. In one embodiment, a CNT-based irradiator includes: at least one CNT-based cathode, itself including: a plurality of carbon nanotubes adjoined to a substrate; a plurality of anodic regions; where each anodic region is configured to emit a distinctly different class of photons in a direction away from the at least one cathode in response to a same reception of electrons; where each of the plurality of anodic regions is operable to receive electrons emitted from at least one of said at least one CNT-based cathode; and where each of the at least one CNT-based cathode and the plurality of anodic regions are disposed within a vacuum encasing.