Er:YAG, CO, and CO(2) laser delivery by ZnS-coated Ag hollow waveguides

ZnS-coated Ag hollow waveguides for Er:YAG, CO, and CO(2) laser light are fabricated based on a sputtering and an electroplating technique. Three types of these waveguides with a 1-mm diameter and a 1-m length are fabricated. Two of them are designed to achieve the minimum loss at the wavelengths of Er:YAG and CO laser light, and the other is for all the lasers. Straight losses of 0.4, 0.5, and 0.25 dB/m are obtained for Er:YAG, CO, and CO(2) laser light, respectively. Because the waveguides are flexible and low loss, they are useful in delivery of mid-infrared lasers in industrial and medical applications.