Electron Trapping Optical Storage Using A Single-Wavelength Light Source for Both Information Write-In and Read-Out

In conventional electron trapping optical storage phosphor, both short- and long-wavelength light are needed for information write-in and read-out, respectively, complicating the optical storage system. Here, a Y₃Al₂Ga₃O₁₂:Pr³⁺,Eu³⁺ optical storage phosphor with Pr³⁺ as an electron donor and Eu³⁺ as an electron trap is designed, and a single wavelength write-read scheme is demonstrated, which employs the same blue laser diode (LD) light source for both optical write-in through two-photon up-conversion charging and for read-out based on photostimulated luminescence (PSL), originated from 4f¹5d¹→4f² transition of Pr³⁺ peaked at 315 nm in UV region. A deep electron trap with the mean depth of 1.42 eV and a narrow distribution of 0.3 eV is observed in the presence of Eu³⁺ in Y₃Al₂Ga₃O₁₂:Pr³⁺, implying its long-term storage potential. The write-in and read-out experiments are conducted using 450 nm blue LD light with the power density of 1 W cm⁻² for write-in and that with a low power density of 0.02 W cm⁻² for read-out in order to avoid the effect of up-conversion luminescence on PSL signal. These results will advance the electron trapping optical storage scheme.