•C. Enkrich1,2, A. Blanco1,3, K. Busch4,2
und M. Wegener1,3,2
1Institut für Angewandte Physik, Universität Karlsruhe
(TH), 76128 Karlsruhe
2DFG-Center for Functional Nanostructures, Universität
Karlsruhe (TH), 76131 Karlsruhe
3Institut für Nanotechnologie, Forschungszentrum Karlsruhe
in der Helmholtz-Gemeinschaft, 76021 Karlsruhe
4Institut für Theorie der Kondensierten Materie, Universität
Karlsruhe (TH), 76128 Karlsruhe
The fabrication of three-dimensional photonic crystals is a major challenge
in materials science, especially when the periodicity lies in the optical
region [1]. Here we present a flexible method based on holographic lithography
[2] to fabricate photonic crystal templates. By interference of four laser
beams it is possible to create 3D microporous structures in a photosensitive
resin (SU-8) arranged in an fcc lattice with the periodicity in the submicron
region [3]. By changing experimental parameters it is possible to tune
their photonic properties. We show that the polymer filling fraction can
be varied from around 20 % to 80 % producing photonic gaps covering a wide
spectral range from the visible to the near infrared. Comparison with theoretical
calculations allows to optimize the design and therefore the photonic properties.
These structures can be used as templates in which materials with a high
dielectric constant can be infiltrated to produce full photonic band gap
crystals.