title: Tapered hollow waveguide for focusing infrared laser beams.
abstract: A tapered hollow waveguide that can focus a laser beam into a small beam spot is proposed for medical and dental applications. We fabricated hollow tapered optics by using a traveling torch, and the shape was formed as a precise linear taper. For a hollow taper tip with input and output diameters of 700 and 200 microm, respectively, the insertion loss is as small as 0.7 dB in a 10 mm long taper. The hollow taper optic producing a 200 microm spot withstands input energy of 100 mJ. Because a focusing lens is unnecessary at the output end, the laser beam can be introduced into a deep and narrow spot with these tapered optics.
authors: Graduate School of Engineering, Yohoku University, Sendai, Japan.
authors: Satoshi
authors: S
authors: Narita
authors: Yuji
authors: Y
authors: Matsuura
authors: Mitsunobu
authors: M
authors: Miyagi