Transverse Magnetic Loss of Metallic Whispering Gallery Waveguides at 10.6Micrometers

摘要

The TM losses of metallic whispering gallery waveguides in the IR have beencalculated for a range of angles of incidence. The allowed angles of incidence have been calculated from the caustic of the rays associated with particular modes. In many practical situations the pseudo-Brewster angle is large compared with the allowed ray angles, so that the usual assumptions must be reconsidered. In that case we find that the TM losses are much lower than generally assumed and that the TM and TE loss ratio is independent of the wall material. Experimental verification of these conclusions is presented.