Curved CO2 laser waveguides for neurosurgery

We have developed a method of fabricating permanently curved hollow metallic waveguides of both constant and tapered inside diameter. This method is based on the use of soluble glass inandrels. In tests with laboratory CO2 lasers we have shown that even without interior dielectric layers these devices can exhibit low loss; e.g., a 22 cm long, 2mm ID guide with a 65° exterior bend transmits more than 90% of properly launched input radiation. We discuss methods of cooling these devices and requirements for their use in neurosurgery.