Tunable Guided-Mode Resonance Filters for Multi-Primary Colors Based on Polarization Rotation

Tunable guided-mode resonance filters (GMRFs) for multi-primary colors based on a twisted nematic liquid crystal (TN-LC) polarization rotator with high peak efficiencies, narrow linewidths, and low sidebands are experimentally demonstrated. The proposed tunable color filter consists of a linear polarizer, the TN-LC polarization rotator, and the GMRF from top to bottom. The polarization of the linear polarized beam generated by the linear polarizer is controlled using a TN-LC. The resonance wavelengths and resonance peaks of the GMRFs are tuned following the orientation of the TN-LC directors. Thus, 3 ~ 6 high saturated primary colors with tunable intensities can be obtained by controlling the applied voltages on the TN-LC of every filter separately.