Developing a conceptual “write”/“read” technology for optical information storage of persistent phosphors is necessary but often underestimated. Here we demonstrate a “write”/“read” approach of traps upon illumination by using a blue light-emitting diode (LED) in persistent phosphors such as LaMgGa₁₁O₁₉:Cr³⁺. Our investigation indicates that the phosphor can be charged upon high-power illumination (e.g., incident power density of 0.5 W cm⁻²) but discharged upon low-power illumination (e.g., 0.1 W cm⁻²). An appealing feature of the present approach is that the charging and discharging share the same illumination wavelength, which offers an interesting technical advantage and apparent convenience for applications. Moreover, such a manipulation technique is generally applicable for many existing phosphors.