Abstract
To seal the end of hollow fibers for medical uses, a sealing cap for Er:YAG laser light is fabricated by fusing a glass ball onto the end of a glass capillary. The cap has a focusing effect and the focal point is located near the cap surface. Optical properties of the caps with a diameter of 1 mm are evaluated, and the lowest insertion loss of 0.27 dB and the highest transmitted pulse energy above 750 mJ have been obtained for the cap made of lowOH silica glass.
