Fabrication of dielectric-coated silver hollow glass waveguides for the infrared by liquid-flow coating method

Polyimide-coated silver hollow glass waveguides with small losses have been fabricated for transmission of Er:YAG laser light. The total loss is around 0.7 dB for the straight waveguide with an inner diameter of 700 micrometers and the length of 2.3 m including a coupling loss from a laser. Even when the waveguide is bent to 180 degrees with a bending radius of 18 cm, the total loss is around 1 dB for the input energy of 500 mJ.