Replication of optical components using a silicone rubber intermediate replica

Silicone rubber may very conveniently be used to cast a mould from a variety of surface-relief optical components and surfaces. From this it is very simple to cast replicas in epoxy resin. The method owes its success in a large part to the flexibility of the rubber mould which eases the process of separation both from the master and from the final replica. However, the flexibility also gives rise to distortions in the final replica. This paper reports preliminary work. to quantify these distortions under various casting conditions.