A diffractive beam homogenizer, based on an array of square, off-axis, continuous-relief diffractive microlenses, for use with an excimer laser has been studied. The homogenizer was originally fabricated by direct-write electron-beam lithography, from which replicas in UV-grade fused silica were made by hot embossing and reactive ion etching. Atomic force microscopy measurements of original and replicated elements showed the accuracy of the replication fidelity. One of the replicated homogenizers was evaluated together with a KrF excimer laser. The homogenized beam had a flat-top profile with 31% of the beam energy contained within an area where the beam intensity was above a threshold level of 90% of the maximum intensity.
|Number of pages||24|
|Journal||Doktorsavhandlingar vid Chalmers Tekniska Hogskola|
|Publication status||Published - 1997|