Upconversion logic gates based on dual-wavelength excitation

Complex logic systems using external excitation sources (1550 nm and 1064 nm lasers) as stimulus inputs and upconversion (UC) emission intensities as the optical outputs signals have been developed by taking advantage of the unique two-wavelength excitation effects. The Er3+ doped β-NaYF4 material that can achieve the emission enhancement via simultaneous dual-wavelength pumping at 1550 and 1064 nm due to the matching energy level. Elementary logic operations (OR, AND, and YES) and integrative logic operations are implemented by observing the change in two visible fluorescence emission bands (Green and Red) under the near-infrared excitation input conditions. The multiple outputs in our system can generate different logic operations under the same input conditions, which could increase the information content in the logic library and further improve the information processing capability. This logic system that takes infrared excitation as input and visible light as output has broad application prospects in the fields of anti-counterfeiting and information encryption. The results not only provide a deep understanding of the dual-wavelength excitation UC luminescence mechanism, but also offer a useful enlightenment for the development of novel micro/nanostructured materials for photonic devices.