| 摘要 |
A method for heating thick-walled glass tubes, particularly quartz tubes, in the manufacture of optical fibres while using microwave energy. According to the invention, the tube (5) is pre-heated to a temperature of about 1000 DEG C.-1500 DEG C., preferably in a known manner with the aid of a gas flame, whereafter the tube is further heated by means of microwave energy, generated by a microwave generator, by inserting the tube (5) axially into a microwave cavity (2) incorporating in both end walls (6,7) or end surfaces openings (3,4) for the tube (5), the electrical field strength being given a field image which includes only one tangential component, according to TE-01n-mode, preferably according to the mode TE-011, whereby the electrical field is so formed as to be tangential to the surfaces of the tube (5), and so formed that the electrical field strength is zero adjacent the surfaces of the cavity (2). The invention also relates to apparatus for carrying out the method.
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