Designed functional optical multilayers
Functional optical materials with designed properties are manufactured.
Pronounced structural colouration of one-dimensional photonic crystals, consisting of alternating layers of high and low refractive index materials is a result of interference of light reflected at the interfaces of the dielectric layers. Their spectral response can be designed by varying a number of key parameters, including the refractive index, the thickness and the number of alternating layers.
Fabrication of Distributed Bragg Reflectors via spin-coating. Our group has established a protocol for producing alternating layers of varying refractive indices by self-assembly of PI-b-PEO block copolymers into inorganic material. The resulting polymer solution is subsequently mixed with TiO2 solution in different ratios. Spin casting allows control over layer thickness. Subsequent heating removes the polymer and the remaining TiO2 is crystalized, leading to layers with high or low refractive indices.