Fast–Slow Red Upconversion Fluorescence Modulation from Ho³⁺‐Doped Glass Ceramics upon Two‐Wavelength Excitation

The control of one light field by another, ultimately at manipulating efficiently photon–photon interactions obsoleting traditional electronic interconnection approach, is an attractive area of research in the development of all‐optical network information science. Herein, an exquisite physical strategy is introduced to realize fast–slow optical modulation of red upconversion (UC) fluorescence from Ho³⁺:LaF₃ nanocrystals embedded glass ceramics (GCs) tailoring by simultaneous two‐wavelength excitation at 980 and 1870 nm laser. An optical modulation of more than 2500% of the red UC fluorescence intensity and a fast response with rise time of 230 µs and decay time of 66 µs as well as a slow response with rise time of 23 ms and decay time of 6.65 ms in the red UC fluorescence signal is shown. The dynamic evolution analysis and theoretical simulations suggest that this fast‐slow optical modulation of red UC fluorescence is rooting from the presence of differentiation of the speed of electrons fully populated in the excited‐state ⁵I₇ regulated by various pumping tactics. The fast–slow optical modulation of red UC fluorescence from Ho³⁺‐doped GCs, manipulating through two‐wavelength excitation at 980 and 1870 nm laser, may find novel application in future all‐optical fiber data processing in various optoelectronic fields.