“…For the practical realization of the proposed multispectral plasmonic color filter, its fabrication dimension is supposed to be finite. Referring to the fabrication method of fully suspended slot waveguide and free-standing plasmonic metal-dielectric-metal filter in literature reports [16,32,33], our designed multilayer plasmonic structure can be realized based on the electron beam evaporation, focused ion beam etching, and chemical gas/solution etching technology. During the practical fabrication process, the precise control of the structural parameters, such as the nanograting thickness, the slit width, the air and SiO 2 layer thickness, the misaligned distance between the upper and bottom nanogratings, etc., are cumbersome to achieve.…”