Energy relays with energy propagation having predetermined orientations

An energy relay, comprising:

• first and second materials having different energy wave propagation properties, the first and second materials being formed to define a structure having first and second relay surfaces;
• and
• wherein the first and second materials each extend between the first and second relay surfaces of the structure and are interspersed across a transverse direction of the structure, such that, the first and second materials are operable to relay energy between the first and second relay surfaces along a plurality of energy propagation paths therebetween;
• wherein, a first energy propagation path of the plurality of energy propagation paths comprises a first end operable to emit or accept energy through a first region of the first relay surface and a second end operable to emit or accept energy through a first region of the second relay surface;
• wherein, the first region of the first relay surface has a first surface normal, the first region of the second relay surface has a second surface normal, and the first and second ends of the first propagation paths have first and second propagation path axes, respectively;
• and
• wherein the energy emitted or accepted through the first region of the first relay surface has a first chief ray whose angular direction is determined by the first surface normal and the first propagation path axis independently of the second surface normal and the second propagation path axis, and the energy emitted or accepted through the first region of the second relay surface has a second chief ray whose angular direction is determined by the second surface normal and the second propagation path axis independently of the first surface normal and first propagation path axis.