Visible light and mid-infrared double-spectrum channel thin film device and preparation method thereof

The invention discloses a visible light and mid-infrared double-spectrum channel thin film device and a preparation method, the visible light and mid-infrared double-spectrum channel thin film device comprises a substrate and a similar long-wave-pass film system arranged on one side of the substrate, and the similar long-wave-pass film system comprises a plurality of high-refractive-index film layers and low-refractive-index film layers which are alternately plated; the high-refractive-index film layer is formed by zinc selenide or zinc sulfide through vacuum resistance evaporation, and the high-refractive-index film layer is in a pressure stress or tensile stress state through ion beam assisted deposition; the low-refractive-index film layer is formed by vacuum electron beam evaporation of fluoride, and the low-refractive-index film layer is in a tensile stress state by ion beam assisted deposition; the substrate is a sapphire substrate. According to the visible light and mid-infrared double-spectrum channel