Abstract

Over the past decade, a number of different types of hollow waveguides have been used for the delivery of CO₂ laser radiation.^1-3 However, much of the previous work has been concentrated on beam attenuation and the power transmission characteristics of the waveguide, whereas to take full advantage of the available CO₂ laser technology, i.e., a combination of high power and high beam quality, it is necessary to try to preserve beam quality in the passage of the beam through the fibre. The principal object of this paper is to investigate the transmission properties of hollow wave guides for the case when high-quality CO₂ laser beams are launched efficiently at the input. In a number of important applications of carbon dioxide lasers, beam quality issues are very important, not only in terms of the achievable spot size, but also as regards the transverse intensity profile.

© 1994 IEEE