Replication technology for holograms and diffractive optical elements

Replication technologies such as embossing, molding and casting are highly attractive for the fabrication of surface relief hologram and diffractive o ptical element (DOE) microstructures. They have very high resolution, typic ally in the nanometer range, and allow the fabrication of a large area, com plex microstructure by low cost, high volume industrial production processe s. Their use is already well established for gratings, white light hologram s, and diffractive foil with typical relief structure shallower than 1 mu M and the extension to the fabrication of deeper and higher aspect ratio mic rostructure is underway The combination of replication technology with othe r processes such as dry etching and shin film coating can also offer new po ssibilities in the design of DOEs suitable for mass production. Replication is expected to become a key technology for the microfabrication of a wide range of DOEs in the future. We review the major hologram and DOE replicati on techniques and describe recent work and results.