| 摘要 |
A large scale mirror is replicated to an optical accuracy in the range of 1 arc minute. An optical master is created by annealing an acrylic liner sheet to a steel substrate in the constant presence of a vacuum. The acrylic is optically polished to complete the master. An epoxy layer is formed on the master. A rigid substrate such as a honeycomb sandwich is provided with a surface closely approximating the contour of the epoxy layer. The substrate is placed over the epoxy layer with a small generally uniform interstice therebetween. Elastomeric material is gently introduced into the interstice while avoiding any stresses, and subsequently cured. Backing irregularity print-through is avoided. Thereafter, the rigid assembly is separated from the master by flexing the acrylic liner. |
