Research On The Reversible Regulation Of Light Emission Of Tungsten Phosphate Glass Based On Photochromic Effect And Its Application In Optical Storage

Transparent glass has been identified as a vital medium for three-dimensional(3D)optical information storage and multi-level encryption.However,it has remained a challenge for directly writing the 3D patterning inside a transparent glass using semiconductor blue laser instead of high-cost femtosecond laser.In addition,inorganic photochromic glasses attract extensive attention due to their application potential in the fields of the holographic memory and 3D optical data storage.Compared with the photochromic films and ceramics,the photochromic glasses are easier to increase the data storage amount in the same volume due to their transparent property.The transparent photochromic glass doped with rare earth ions can modulate its luminescent properties through the external light field,then the application field of luminescent glass is expanded.Therefore,the development of photo-modulated glass is urgently needed to realize the 3D optical information storage applications.The tungsten phosphate glasses doped with rare earth ion Eu³⁺was prepared by the traditional high temperature solid phase melting method.The effects of Sb₂O₃ on the transparency and luminescence properties of glass were investigated.The Sb₂O₃addition stabilizes the valence state of W⁶⁺,thus the transparent tungsten phosphate glasses are obtained.The glasses have photochromic effect under the irradiation of473nm laser,and decoloration of photochromic glasses are obtained by the thermal stimulation.After several cycles,it shows good reversibility.The change of valence states of W and Sb in glass reveals the mechanism of reversible discoloration.Since the emission peak of Eu³⁺overlapped with the absorbance of photochromic glass,the emission of Eu³⁺could be absorbed by the host of blue glass to regulate the emission through photochromic regulation and achieve a photoluminescence regulation rate of68%.The complex information patterns can be written and erased in the photo-modulated glass,showing the ability of the reversible 3D optical data storage.In addition,the optical information written in the arbitrary 3D space of transparent glass can be hierarchically discriminated,demonstrating the information encryption function.The transparent photo-modulated glass is of importance for extending their new applications in the optoelectronic fields.In order to further develop new applications of luminescence regulation,the tungsten phosphate up-conversion luminescence glasses co-doped with the rare earth ion Er³⁺/Yb³⁺were prepared by the same method.Moreover,up-conversion luminescence is a non-linear optical process,which requires two or more low energy near infrared(NIR)photons to generate a higher energy photon through a multi-step energy transfer,with a large anti-Stokes shift.This property is of special significance for the application of photosensitive materials in three-dimensional optical storage devices,which not only provides high three-dimensional spatial resolution,but also avoids new photochromic reactions by multi-photon absorption,realizes remote control and non-destructive up-conversion luminescence reading.The reversible up-conversion luminescence properties of the transparent photochromic glass were instigated.The reversible color change of tungsten phosphate glass from a bit yellow to blue was observed upon alternating 473 nm laser and thermal stimulation.The reversible modulation of the up-conversion luminescence from glass was achieved by its photochromism.That information data can be written and erased repeatedly in transparent glass,and optical information can be read by up-conversion luminescence control,the new application of lossless information readout is presented.