Distal tips for hollow glass waveguide delivery systems

Hollow glass waveguides are an increasingly popular fiber- based delivery system for IR laser power. They are low loss and can be bent to radii less than 3 cm while maintaining an excellent modal distribution. The additional loss due to bending has been shown to scale linearly with the inverse of bending radius. For small bending radii however, this bending loss has bene shown to increase beyond this trend due to mode mixing. Oscillating modes have been observed by varying the radius of curvature for a waveguide bent into a single compete loop. Curved HGW distal tip prototypes of bore sizes 530 and 320 micrometers , were made and exhibited a 0.56 and a 0.17 dB increase in loss respectively over the straight waveguides.