ABSTRACT

The physical copying of surface-relief microstructures by replication techniques such as hot embossing, moulding or casting is expected to become a key technology for the low-cost mass-production of diffractive optical elements (DOEs) and other micro-optical elements with micrometre-or nanomctre-sized features. These replication processes arc capable of achieving nanometre resolution over large areas and the cost of replicated microstructures is relatively independent of the complexity of the detailed structure. Replication technology is already used for the commercial production of submicron grating structures (hot embossed diffractive foil and security holograms) and data storage microstructures (injection moulded compact discs). The commercial replication of micro-optical clements requires further development to routinely handle the deeper and finer microstructures typical for elements such as refractive and diffractive microlenses, binary optics and other phase DOEs.