| 摘要 |
<p>A mirror substrate, in particular for use in astronomical optics, comprises two symmetrical preformed plates of glass (10, 12) glued by their respective inside faces (26, 28) on either side of an intermediate structure (14), the outside face (38) of one of the plates (10) being suitable for subsequently receiving a reflecting coating. The intermediate structure (14) is a composite structure made of glass foam which is substantially uniform in nature, and in the preferred embodiments it comprises a central core (16) of glass foam together with two sets (18 and 20) of blocks of glass foam.</p> |
