Hollow microstructural waveguides for propagation of infrared radiation

Theoretical results are presented on the propagation of infrared radiation in micron-sized parallel plane waveguides whose walls are gold-coated and separated by empty space. Propagation characteristics of the TE/sub 10/, TM/sub 10/, and TEM modes are described. The most loss-free propagation occurs for the TE/sub 10/ mode, due to the high reflectance for s polarization at the gold-coated surface. The results, when extrapolated to propagation in hollow micron-sized waveguides of rectangular cross section, suggest that propagation is possible over a significant number of wavelengths in spite of the large circumference of such guides in relation to their cross-sectional area. Theoretical indications are that the most loss-free structures would have losses on the order of 0.3 dB/cm.<
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