Emission of visible light by dyes in both liquid and polymer hosts is reported when excited by simultaneous absorption of infrared light from two different wavelength sources. By moving the intersection point of these two beams about within the volume of the dye-doped medium, one can create a true, real-time, three-dimensional display.
Applied Physics Letters
Rapaport, Alexandra; Ayrault, Karine; Matthew-Daniel, Eyitope St.; and Bass, Michael, "Visible light emission from dyes excited by simultaneous absorption of two different frequency beams of light" (1999). Faculty Bibliography 1990s. 2801.