Crystal ordering of colloidal self-assembled photonic crystals fabricated by vertical drawing deposition
technique has been improved following application of acoustic noise vibrations. The scanning electron
microscopy has confirmed the improvement in the crystal order on the surface (111) plane and has
demonstrated that thin opal films crystallized under acoustic agitation consist of similarly oriented crystallites,
the characteristic transverse dimension of which is larger compared to that of sample grown without acoustic
field. Three-dimensional lattice arrangement of the opal crystal has been examined by means of laser
diffraction and optical transmission spectroscopy. Novel approach towards optical characterisation of the opal
crystallinity has been suggested.
We study the role of noise during the growth process of opal-based photonic crystals, and demonstrate
that noise significantly improves their structural properties. We observe a stochastic resonance-like
behaviour, where the ordering of the resulting structure improves up to a certain optimal noise level
and then deteriorates for larger noise volumes. This demonstrates that noise can have a nontrivial
effect when applied during a non-equilibrium pattern forming process.