Propagation of infrared radiation in hollow microstructural cylindrical waveguides

Theoretical and numerical results are presented on the propagation of infrared radiation in TE/sub 01/-, TM/sub 01/-, and TE/sub 11/-like modes in an empty cylindrical, gold-coated waveguide of micron dimensions. Low-loss propagation is possible for the TE/sub 01/-like mode, whose configuration is similar to that of the TE/sub 01/ mode in a guide with perfectly conducting walls. Propagation is more lossy for the TM/sub 01/- and TE/sub 11/-like modes. While for small guide radii these modes resemble the TM/sub 01/ and TE/sub 11/ modes in a guide with perfectly conducting walls, they transform into surface waves as the guide radius is increased, with losses that are independent of guide radius. >