Using a single layer of metallic film at the nanometer scale, mechanical engineering assistant professors Xiaodong Yang and Jie Gao are creating vivid full-color, high-resolution holographic images. The research could lead to 3-D floating displays — like emojis — and big data storage, but also shows promise for credit card security marking and biomedical imaging.
The pair of researchers use focused ion beam milling to drill tiny rectangular holes in the film layer. Under a scanning electron microscope, the hologram they produced looks like a needlepoint pattern.
Different combinations of red, green and blue laser light on the surface at various orientation angles allow the researchers to produce holograms within the entire visible color range.
Their work was published in the journal ACS Nano in September.