Diffractive microlenses replicated in fused silica for excimer laser-beam homogenizing

Autor: Fredrik Nikolajeff, Bernard Curtis, Sverker Hård
Rok vydání: 1997
Předmět:
Zdroj: Applied Optics. 36:8481
ISSN: 1539-4522
0003-6935
DOI: 10.1364/ao.36.008481
Popis: 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. We originally fabricated the homogenizer by direct-write electron-beam lithography, from which we made replicas in UV-grade fused silica 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.
Databáze: OpenAIRE
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