Efficient Multi-layered Trans-Reflective RGB- CMY Colors Filters for Optical Communication

Abstract

Multi-layered Trans-Reflective RGB- CMY colors filters for optical communication are discussed. Trans-reflective color filters have the potential to advance not only in the fiber optics communication industry but also in the signal-processing sector. Moreover, thin-film color filters for contrast enhancement and imaging, enclosed in fiber optics are used in precision equipment for diagnostics of ailments and thus, saving lives. In the proposed design of a trans-reflective color filter, a semiconductor thin-film of Si with TiO2 both act as dielectric layers on reflecting surfaces Ag. These layers are used for selective spectral light absorptions to get pure CMY and RGB colors. The proposed color filter consists of an MDMD configuration where one dielectric layer consists of two variable thin dielectric layers of Si and TiO2 sandwiched between two metallic mirror layers of Ag. These metal layers along with dielectric layers are vital for phase compensation, which is directly dependent on the thickness of each layer. The thin-film semiconductor layer of Si with TiO2 in the middle of these metallic mirrors plays a crucial part in achieving high purity of colors in the visible range. By altering the thickness of dielectric layers, it is observed that the purity of colors in transmission and reflection bands widely changes. The significance of designing these five-layers based thin-film filters is that they provide a superior resonance response that helps not only in achieving high pure RGB colors in transmission but also in CMY colors in reflection.