Guided beams in concave metallic waveguides

A new waveguiding technique employs a single concave metallic strip as the guiding medium. With appropriate curvature of the strip, the beam modes may be described in terms of Hermite-Gaussian functions parallel to the strip and Airy functions in the perpendicular direction. Such devices would be especially useful in frequency or power regimes where appropriate dielectric waveguides are not available. Experiments have been performed with concave waveguides formed to circular and helical geometries.