Low-loss propagation and polarization rotation in twisted infrared metal waveguides

Abstract
Low‐loss propagation of 10.6‐μm light has been demonstrated in hollow metal waveguides of rectangular cross section that undergo axial twists. These twisted waveguides can serve as efficient infrared polarization rotators, where greater than 90% transmission has been achieved at 10.6 μm for a 90° rotation. In addition, transmission of more than 200 W cw through flexible waveguides is reported here, confirming that these waveguides are potentially useful for steering high‐power infrared light beams.