1 Optofluidics, Department of Micro- and Nanotechnology, Technical University of Denmark2 Department of Micro- and Nanotechnology, Technical University of Denmark3 Polymer Microsystems for Cell Processing, Department of Micro- and Nanotechnology, Technical University of Denmark4 Centre National de la Recherche Scientifique5 Saint-Gobain Recherche6 Center for Nanostructured Graphene, Center, Technical University of Denmark
Enhanced control of diffraction through transparent substrates is achieved via disordered gratings in a silica sol–gel film. Tailoring the degree of disorder allows tuning of the diffractive behavior from discrete orders into broad distributions over large angular range. Gratings of optical quality are formed by silica sol–gel nanoimprint lithography and an optical setup for the measurement of continuous diffraction patterns is presented. Sound agreement is found between measurements and simulation, validating both the approach for redirection of light and the fabrication process. The disordered gratings are presented in the context of improved interior daylighting and may furthermore be suited to a wide variety of applications where controlled angular redirection of light is desired.