| 摘要 |
The present invention relates to a method which is characterised in that: a) a polymerisable mixture of the core polymer is polymerised in order to form a cylindrical rod; b) this cylindrical rod is placed inside a cylindrical cavity in such a way that the axes coincide; c) the space existing between the internal walls of the cavity and the rod is filled with a mixture of the cladding polymer to be polymerised; d) the mixture is polymerised in situ and; e) the step index preform thus obtained is then removed. <IMAGE> |
