White and full color upconversion film-on-glass displays driven by a single 978 nm laser

White and full-color displays based on upconversion (UC) processes in multilayered NaLu₁-x-yYbxTmy(WO₄)₂/NaLu₁-x-zYbxHoz(WO₄)₂ films deposited on 20 × 20 mm² Pyrex glass substrates are demonstrated by scanning with a 978 nm focused beam from a diode laser. Moreover, spatially resolved red, green and blue pixels are selected by focusing the excitation light at different depths on three stacked films with compositions individually optimized for UC emission of each fundamental color. The highest temperature used in synthesis/deposition process was 580 °C allowing the use of glass substrates.