Replication of diffractive microoptical elements using a PMMA molding technique

Diffractive optical elements have been replicated by using a molding process in polymethyl methacrylate (PMMA). A two-dimensional lenslet array with eight discrete phase levels was first fabricated on a quartz glass substrate by using optical lithography and reactive ion etching. This substrate was then pressed into the PMMA plastic. The molding process took place in an evacuated oven at a temperature above the melting point of the PMMA. We describe the copying process and show that were obtained with the replicated lenslet array