Anti-counterfeiting applications by photochromism induced modulation of reversible upconversion luminescence in TiO 2 :Yb 3+ ,Er 3+ ceramic

Reversible photochromism and reversible UCL modulation of TiO 2 :Yb 3+ ,Er 3+ ceramics were reported when alternating 405 nm LED and 808 nm laser irradiation. The photochromic TiO 2 :Yb 3+ ,Er 3+ ceramics are promising materials in the field of anti-counterfeiting.