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Free keywords:
Micro- and nanostructured optics, manufacturing
technologies, top-down and bottom-up lithography, subwavelength
structuring, moth-eye structures, self-assembly, bionics
and biomimetic concepts.
Abstract:
In nature, optical structures in the subwavelength
range have been evolved over millions of years. For example,
in the form of ‘moth-eye’ structures they show a strong antireflective
effect on the compound eyes of night-active insects
and therefore offer a successful protection over predators. In
this contribution the advantages and challenges to transfer this
natural concept of subwavelength structured optical interfaces to
high-end optical systems are discussed. Here, in comparison to
alternative conventional multilayer systems, the bioinspired antireflective
structures offer a wide wavelength range and a broad
angle dependency. Additionally, adhesion problems are reduced
drastically. Simultaneously to the theoretical consideration of the
best profile form of the subwavelength structures, appropriate
realization technologies have been developed in recent years,
where both top-down and bottom-up approaches have been
investigated. Depending on the choice of the structuring technique,
anti-reflective subwavelength structures are applicable to
a wide spectrum of optical elements ranging from micro-optical
components to aspheres for applications in imaging and also
illumination setups of high-end optical instruments.
