Design and fabrication of structural color filters with polymer-based guided-mode resonant gratings by nanoimprint lithography

We investigate structural color filters theoretically and experimentally using polymer-based guided-mode resonant gratings fabricated by nanoimprint lithography. Each grating area is 200 x 200μm ² , which is a suitable pixel size for displays and multichannel detectors. In the mold fabrication, electron beam lithography and fast atom beam etching are used. The grating periods are 600, 350, and 300 nm for the red, green, and blue filters, respectively. Reflectivity is measured as a function of wavelength. The wavelength at peak reflectivity is proportional to the grating period as expected from the calculated results. At a wavelength of 572.0 nm, maximum reflectivity of 58.3% is obtained for the 400-nm-period grating with a bandwidth of 17.5 nm.