Fabrication of germanium-coated nickel hollow waveguides for infrared transmission

Abstract
Circular hollow nickel waveguides with an inner germanium layer are fabricated by using a method based on rf sputtering, plating, and etching techniques. Transmission losses less than 0.5 dB are achieved including launching losses for straight waveguides with 1.5 mmφ×1 m at 10.6-μm wavelength. Bending losses of the waveguides are also examined.