Thin film epoxy replication is idealy suited for the production of high quality optics. Flat surfaces to 1/10 wave accuracy are economically replicated onto metal substrates of aluminum for minimum cost and on beryllium for minimum inertia. Surface preparation is critical to obtaining good replicas. Aspheric optics are producedon both glass and metal substrates; glass being sutable for optics that do not deviate substantially from a sphere and metal being preferred for fast or difficult aspherics. A generalized aspheric telescope replicated on glass yielding near diffraction limited performance is described as an example of one of the more difficult replications.
Harold M. Weissman,
"State Of The Art In Thin Film Epoxy Replication", Proc. SPIE 0306, Contemporary Methods of Optical Fabrication, (31 March 1982); doi: 10.1117/12.932713; https://doi.org/10.1117/12.932713