Polarization-dependent reflective color filter incorporating an embedded silicon grating

A reflective color filter showing polarization dependent is proposed, where on a SiO2 substrate, a Si-grating is embedded inside a dielectric Si3N4 overlay. By varying the period of the grating, cyan, magenta and yellow (CMY) colors are gained for the transverse electric (TE) polarized incidence. With the polarization of incident light changed from TE polarization to transverse magnetic (TM) polarization, the structure’s reflective color varies accordingly. Therefore, the proposed structure has application prospects in the field of anti-counterfeiting and color display.