Abstract

Hollow optical waveguides are currently of great interest as flexible guides for Er:YAG laser power transmission in medical and dental applications. Other important uses are for CO₂ laser transmission and high-power laser traitsmission at all wavelengths. The use of a dielectric cladding surrounded by a layer of metal has been shown to work, either on glass or plastic substrates.¹ But because of the presence of the metal layer, the waveguide cannot be fabricated by standard optical-fiber-making techniques. Instead, it must be built up directly on capillary tubing. The use of a dielectric Bragg reflector (not to be confused with Bragg gratings in fiber) to guide light in a hollow waveguide has been considered in conjunction with a metal layer² at the outer extent of the dielectric layers. In this paper, these ideas are extended to include that of an all-glass hollow waveguide with a reflective cladding similar in concept to the quarter-wave stack used in bulk multilayer reflective optics. A theoretical study of this structure is presented. The hollow waveguide could be made as preforms and then drawn into fiber at a significantly lower cost than the current techniques. We have analyzed the proposed structure and found a theoretical attenuation of less than 1 dB/m.

© 1996 Optical Society of America