Small-bore, polymer-coated hollow fibers for medical infrared lasers

For medical applications, a hollow fiber is an effective delivery medium for infrared lasers represented by Er:YAG and CO/sub 2/ lasers which common silica glass fibers cannot transmit due to the absorption. We have developed hollow fibers with a polymer thin film upon the inside of silver-coated glass capillary tube and shown their low loss properties for high-powered infrared lasers. In this paper, we report the results on small bore hollow fibers with the bore sizes of 320 /spl mu/m and 250 /spl mu/m which we newly developed for medical applications requiring highly flexible fibers or targeting laser beam at very small objects.