| 摘要 |
In the method the gas for the reactive deposition of the glass material is guided through a channel (2) surrounding the rod-shaped or tubular starting object (1). For externally coating the starting object (1), a plasma zone (3) surrounding the starting body is generated in the channel (2) by a resonator (4), deposition of the glass material on the inner wall of the channel (2) being either prevented or at least minimised in that the field strength of the resonator (4) at the inner side of the channel (2) is small. In a different embodiment, a protective gas layer, such as an oxygen stream, can be maintained on the inner side of the channel (2) so that no significant deposition of glass material takes place on the inner wall of the channel (2) surrounding the starting object (1). Especially blanks for producing optical waveguides with a large core/sheath ratio can thereby be made in controlled atmospheres with a good degree of gas utilisation. <IMAGE> |
