Membrane-type polarization-controlled color filters on silicon substrate

Two polarization-controlled color filters (CF), named CF-I and CF-II, are designed and implemented on an HfO2-on-silicon platform. The devices are with a 200-nm-thick membrane structure realized by etching the silicon substrate beneath the grating patterns away. The spectral responses are characterized by a micro-reflection measurement system. CF-I outputs blue and green colors and CF-II generates yellow and red colors, for normal incident TM- and TE-polarized waves, respectively. Detailed results and analyses on them are also provided both theoretically and experimentally. Particularly, the achieved membrane-type color filters have the potential of being transferred from the silicon substrate to other foreign platforms by breaking off the support beams mechanically, and thus may be applied in several fields such as image sensors, display elements, and even wearable devices.