| abstract |
A flexible material for optical applications in a wavelength range of λ 1 to λ 2 , λ 1 being smaller than λ 2 , composed of a flexible support and at least one multilayer that comprises a porous or nanoporous layer which has a low refractive index and contains inorganic nanoparticles and at least one binder, and a non-porous polymer layer which has a high refractive index and is in direct contact with the porous or nanoporous layer; said flexible material is characterized in that the maximum thicknesses of the boundary layers, in which the refractive index changes from one value to the other and which are located between the porous or nanoporous layers and the non-porous polymer layers that are in direct contact therewith, amount to 0.2 times wavelength λ 2 ; and the difference in the refractive indices of the porous or nanoporous layers and the non-porous polymer layers is at least 0.20, 200 nm and 2500 nm being typical values for λ 1 and λ 2 . |