| Abstract: | A metallic waveguide tuned to an infrared region of interest provides
spectral and spatial control over emitted/absorbed thermal radiation. The
ratio of the depth of the waveguide to the smallest lateral dimension
thereof is such that that the lateral dimension provides spectral
selectivity and that the waveguide is deep enough for a fixed lateral
dimension to establish directionality but is not so deep that it incurs
severe ohmic losses. A panel with an array of such waveguides directs
thermal radiation from a body in a specific direction and with a spectral
response that is the result of the physical dimensions of the individual
waveguides that make up the waveguide array and the arrangement of the
waveguides in the array. The waveguide axis may be obliquely oriented
with respect to the substrate normal so as to impart non-normal
directionality to the emitted radiation with respect to the substrate
normal surface. |