Cyclic olefin polymer-coated silver hollow glass waveguides for the infrared

Cyclic olefin polymer (COP) is newly used as the inner dielectric of infrared, hollow glass waveguides because of its low extinction coefficient in the mid-infrared region. A liquid-flow coating and dry-cure process are employed to form the COP layer on the inside of a silver-coated hollow glass tube. In the coating process, cyclohexane is chosen as the solvent of COP to form a smooth and uniform COP layer. It is shown that COP-coated silver hollow glass waveguides show low loss properties for CO2, CO, and Er:YAG laser light when the thickness of the COP layer is properly chosen.